Preparing for the USA Computing Olympiad (USACO) requires a structured learning schedule, determination, and practice. Here's a step-by-step guide to help you build an effective learning plan:

1. **Understand the Basics:**

   - Familiarize yourself with the rules, format, and difficulty levels of USACO contests.

   - Explore past contest problems and their solutions on the USACO website.

2. **Choose a Programming Language:**

   - Select a language you're comfortable with for competitive programming. Common choices include C++, Python, and Java.

3. **Learn Data Structures and Algorithms:**

   - Develop a strong foundation in data structures (arrays, lists, stacks, queues, trees, graphs) and algorithms (sorting, searching, dynamic programming, etc.).

   - Study books like "Introduction to Algorithms" by Cormen, Leiserson, Rivest, and Stein, and take online courses or tutorials on data structures and algorithms.

4. **Practice Contest Problems:**

   - Start with the USACO Training Gateway, which offers a variety of problems and solutions.

   - Use online judges like Codeforces, AtCoder, and LeetCode to practice similar problems.

5. **Participate in Contests:**

   - Join local programming contests or online contests regularly to build your problem-solving skills under time pressure.

   - Use platforms like Codeforces, TopCoder, and CodeChef to compete in contests.

6. **Read and Analyze Solutions:**

   - After solving problems or participating in contests, study the solutions of others, especially those with higher ratings.

   - Understand different approaches, algorithms, and coding styles.

7. **Review and Refine Your Code:**

   - Maintain a personal library of algorithms and code snippets for quick reference during contests.

   - Keep your code clean, efficient, and well-documented.

8. **Simulate Contest Conditions:**

   - Practice by simulating real USACO contest conditions—use the same environment and time constraints.

   - Refrain from using external help during practice contests.

9. **Participate in Mock Contests:**

   - Join online platforms that offer mock USACO contests. These contests mimic the official USACO experience.

10. **Master USACO-Specific Topics:**

    - USACO often features topics like depth-first search (DFS), breadth-first search (BFS), dynamic programming, greedy algorithms, and more. Focus on mastering these.

11. **Read and Review Problems:**

    - Carefully read the contest problems and understand their requirements before starting to code.

    - Test your code thoroughly on sample inputs and edge cases.

12. **Time Management:**

    - Allocate time for learning, practice, and taking breaks. Regular, consistent practice is more effective than occasional cramming.

13. **Seek Help and Collaborate:**

    - Join online forums or communities where you can ask questions and discuss problems.

    - Collaborate with other competitive programmers to learn and grow together.

14. **Stay Updated:**

    - Keep an eye on the USACO website and mailing list for announcements about contests, dates, and rule changes.

15. **Stay Persistent:**

    - Competitive programming can be challenging, but persistence is key. Don't get discouraged by initial failures; keep practicing and learning from your mistakes.

Remember that consistent practice, a solid understanding of algorithms and data structures, and the ability to think critically and creatively are the keys to success in USACO. Good luck with your preparations!

BEIJING (Reuters) - China's aviation industry sank further into the red, losing 34.25 billion yuan ($4.89 billion) in the second quarter, only slightly narrower than in the first quarter, underlining the colossal financial impact from the coronavirus pandemic.

In the first quarter the industry, which includes airlines, airports and other aviation companies, lost 38.1 billion yuan, according to data released by the Civil Aviation Administration of China (CAAC) on Friday.

China's aviation industry has been recovering faster than most countries emerging from the COVID lockdowns, underpinned by a steady recovery in the domestic travel market after the epidemic was largely brought under control.

But passenger numbers showed the sector is still way below pre-COVID-19 levels, according to the latest official data. June passenger numbers fell 42.4% from a year earlier to 30.74 million, the CAAC said, although that was better than a 52.6% decline in May.

In the first half this year, total passenger numbers dropped by 45.8% from a year ago.

To boost cashflows, a few Chinese airlines have recently rolled out discount passes that would allow passengers unlimited domestic travel with few restrictions. China Eastern Airlines (SS:600115) is the first in June to sell "fly at will" flight passes for unlimited weekend domestic travel until the end of the year.

The deal was met with great consumer enthusiasm and more airlines followed suit. Hainan Airlines (SS:600221) this month offered consumers flight passes that would enable them to make unlimited trips to or from Hainan island, a popular tropical tourist spot.

TOKYO (Reuters) - International Monetary Fund Chief Economist Gita Gopinath said on Friday governments must shift to "equity-like" support from one focused on liquidity provision as the coronavirus pandemic inflicts prolonged harm on companies.

Government support in the form of loans would saddle companies with huge debt, which would serve like a tax that makes it difficult for them to emerge from the crisis, she said.

"If the lending takes form more like equity ... then that's less onus on the firms. That will make it easier for firms to recover from the crisis," Gopinath said in a webinar co-hosted by the IMF and the University of Tokyo.

TOKYO (Reuters) - Japan is likely to revise its economic assessment up slightly at its monthly report for July, government officials said, nodding to growing signs the economy is gradually emerging from the impact of the coronavirus pandemic.

The change in assessment, which would be the second straight month of upgrade, would reflect a rebound in service-sector sentiment and signs of recovery in exports to China, the officials told Reuters on condition of anonymity as they were not authorised to speak publicly.

In June, the government said that the economy was in a severe state but that it was showing signs of bottoming out.

By Nate Raymond

BOSTON (Reuters) - A federal appeals court on Thursday cleared the way for prosecutors to seek longer prison sentences for a founder and supervisory pharmacist of a Massachusetts compounding pharmacy whose tainted drugs sparked a deadly fungal meningitis outbreak in 2012.

The 1st U.S. Circuit Court of Appeals in Boston upheld the racketeering and fraud convictions of Barry Cadden, New England Compounding Center's ex-president, and Glenn Chin, its former supervisory pharmacist.

But the three-judge panel said a trial judge erred in sentencing Cadden, 53, and Chin, 52, to nine and eight years in prison, respectively, when he declined to apply various federal sentencing guideline enhancements.

U.S. Circuit Judge David Barron said the judge, among other things, in calculating a sentence wrongly concluded only the hospitals that bought NECC's drugs could count as victims and not the patients who used them.

But the court also ruled the judge did not wrongly undercalculate the victims' financial losses, which posed "the greatest risk of substantially increasing our client's sentence," said Bruce Singal, Cadden's lawyer.

Prosecutors had cited larger losses in seeking 35-year prison terms.

Both men were indicted in 2014 after a fungal meningitis outbreak traced back to mold-tainted steroids that prosecutors say NECC produced in filthy and unsafe conditions and shipped to hospitals and clinics nationally.

The outbreak sickened 793 patients, more than 100 of whom have died, prosecutors said.

Jurors in separate trials in 2017 acquitted Cadden and Chin of second-degree murder charges related to the deaths of 25 patients but convicted them of racketeering and fraud over alleged misrepresentations made to NECC's customers.

Prosecutors argued hospitals would not have bought drugs from Framingham, Massachusetts-based NECC had they known about its quality control issues.

Cadden and Chin also face separate second-degree murder charges in Michigan, which was hit hard by the outbreak.

WASHINGTON (Reuters) - President Donald Trump will sign three executive orders on lowering prescription drug prices, White House Chief of Staff Mark Meadows said on Thursday.

"This president is going to do three different executive orders that will substantially make sure that the average American gets to pay less for their prescription drugs," Meadows said in an interview on Fox Business Network.

Meadows did not give details and did not say when the executive orders would be signed.

On Monday, Meadows told Fox News the White House was looking to get something done on prescription drug prices after Congress failed to act.

Trump is trailing Democratic presidential candidate Joe Biden in opinion polls ahead of the Nov. 3 election and the cost of healthcare is a major issue in the campaign.

The Democratic-controlled House of Representatives on Monday passed a healthcare bill that includes provisions to cut prescription drug prices. The legislation is expected to be blocked in the Republican-controlled Senate.

By Dan Burns

(Reuters) - The U.S. Federal Reserve's holdings of bonds and other assets shrank for a fourth straight week, sliding below $7 trillion, and use of one key emergency liquidity measure dropped to zero in the latest sign that financial stresses that erupted early in the coronavirus pandemic have eased.

The Fed's total balance sheet size declined by about $88 billion to $6.97 trillion as of July 8 versus $7.06 trillion a week earlier, data released on Thursday by the central bank showed.

It was the largest weekly drop in more than 11 years, and the main driver was the balance of outstanding repurchase agreements - or repos - which fell to zero from $61.2 billion a week earlier. It was the first time in 10 months that banks have not tapped the Fed for this key source of short-term funding.

"In a sense, it is the end of an era," Jefferies (NYSE:JEF) economists Thomas Simons and Aneta Markowska wrote in a research note emailed Thursday afternoon.

The Fed began intervening in the repo market in mid-September after a shortfall of bank reserves led to a record surge in short-term borrowing costs. It ramped up that support to unprecedented levels in March after concerns over the rapidly spreading coronavirus disrupted financial markets.

Take-up of the Fed's repo operations waned over the past few months as markets stabilized and the Fed provided more liquidity through massive purchases of Treasury securities and mortgage-backed securities.

The central bank also tweaked the repo operations in June to make them slightly more expensive, positioning them as more of a backstop. That appears to be pushing banks to find private counterparties for their repo needs.

As evidence, there were no bids for a fourth straight day at Thursday's overnight repo offering from the Fed. Officials have pledged to keep monitoring financial conditions and offer more support if needed.

"They want to be seen as supplying more than enough to the system and they're going to err on the side of doing that," said Kathy Bostjancic, chief U.S. financial economist for Oxford Economics.

By Daphne Psaledakis, Alexandra Alper and Matt Spetalnick

WASHINGTON (Reuters) - The United States on Thursday imposed sanctions on the highest ranking Chinese official yet targeted over alleged human rights abuses against the Uighur Muslim minority, a move likely to further ratchet up tensions between Washington and Beijing.

Washington blacklisted Xinjiang region's Communist Party Secretary Chen Quanguo, a member of China's powerful Politburo, and three other officials. The highly anticipated action followed months of Washington's hostility toward Beijing over China's handling of the novel coronavirus outbreak and its tightening grip on Hong Kong.

A senior administration official who briefed reporters after the announcements described Chen as the highest ranking Chinese official ever sanctioned by the United States.

The blacklisting is "no joke," he said. "Not only in terms of symbolic and reputational affect, but it does have real meaning on a person's ability to move around the world and conduct business."

The Chinese embassy in Washington did not respond to a request for comment. But China has denied mistreatment of Uighur Muslims and says the camps provide vocational training and are needed to fight extremism.

The sanctions were imposed under the Global Magnitsky Act, which allows the U.S. government to target human rights violators worldwide by freezing any U.S. assets, banning U.S. travel and prohibiting Americans from doing business with them.

Sanctions were also imposed on Zhu Hailun, a former deputy party secretary and current deputy secretary of regional legislative body the Xinjiang's People's Congress; Wang Mingshan, the director and Communist Party secretary of the Xinjiang Public Security Bureau; and former party secretary of the bureau Huo Liujun.

U.S. Secretary of State Mike Pompeo said Washington was also barring Chen, Zhu, Wang and their immediate families, as well as other unnamed Chinese Communist Party officials, from traveling to the United States.

U.S. Republican Senator Marco Rubio, who sponsored legislation signed by U.S. President Donald Trump in June that calls for sanctions over the repression of Uighurs, told Reuters the move was "long overdue" and that more steps were needed.

"For far too long, Chinese officials have not been held accountable for committing atrocities that likely constitute crimes against humanity," Rubio said.

Despite Trump's hardline public remarks about Beijing, former national security adviser John Bolton alleged in his recent book that Trump said Chinese President Xi Jinping should go ahead with building detention camps in Xinjiang and sought Xi's help to win reelection in November.

Trump said in an interview last month he had held off on tougher sanctions on China over Uighur human rights due to concerns such measures would have interfered in trade negotiations with Beijing.

Treasury Secretary Steven Mnuchin had also raised objections to the Treasury sanctions, especially against a Politburo member, out of concerns they could further damage U.S.-China relations, according to a person familiar with the matter.

"The United States is committed to using the full breadth of its financial powers to hold human rights abusers accountable in Xinjiang and across the world," Mnuchin said in a statement.

Peter Harrell, a former U.S. official and sanctions expert at the Center for a New American Security, said Thursday's move may signal a continued shift by the Trump administration of "paying more attention to human rights abuses in China ... after several years of relative neglect."

Chen made his mark swiftly after taking the top post in Xinjiang in 2016, when mass "anti-terror" rallies were held in the region's largest cities involving tens of thousands of paramilitary troops and police. He is widely considered the senior official responsible for the security crackdown in Xinjiang.

The United Nations estimates that more than a million Muslims have been detained in camps in the Xinjiang region.

CARACAS (Reuters) - Venezuela's congress on Thursday said it hired two U.S. firms to manage $80 million seized from President Nicolas Maduro's government after Washington disavowed it and recognized opposition leader Juan Guaido as the country's legitimate president.

Opposition leaders are hoping to use some of the funds to provide stipends for doctors and nurses working on the front lines of the coronavirus epidemic.

Delaware based companies BRV Disbursement Co. LLC and BRV Administrator Co. LLC will manage the resources in exchange for $1.25 million, congress said in a statement.

Reuters was unable to obtain comment from the firms, which do not appear to have websites.

Guaido does not control Venezuela's state institutions or armed forces, but his allies control offshore assets including refiner Citgo and some funds that had been held by Maduro's government in U.S. accounts.

Despite a sweeping set of sanctions enacted in early 2019, Guaido's allies have struggled to obtain access to funds frozen in the United States due in part to the stringent requirements of U.S. authorities.

Maduro's government has accused Guaido and others of stealing the nation's resources with the help of the Trump administration.

(Bloomberg) -- South Korea’s government is preparing new regulations to curb excessive house price gains that have fueled public discontent over inequality and property speculation.

Affordable housing has been one of President Moon Jae-in’s key policy objectives since taking office in May 2017 with a vow to improve the living standards of a wider range of people. Yet a mismatch of supply and demand in popular neighborhoods and widespread investment purchases have seen prices soar in Seoul.

South Korea Urges Officials to Sell Homes as Prices Fuel Anger

Record-low interest rates aimed at supporting the virus-hit economy have also contributed upward pressure on prices. Politicians with multiple homes have further complicated the issue by giving the impression they are benefiting from the circumstances.

The Moon administration has already unleashed a series of measures that have cooled price increases in many parts of the country. The challenge is to come up with further steps that can address the remaining pockets of soaring prices without buckling the wider property market or limiting potential stimulus for a sputtering economy.

South Korea’s overheating property market has been largely confined to Seoul and its surrounding areas, with prices broadly stable in other large cities and declining in some smaller regions over the past three years.

The average apartment price in Seoul surged more than 50% to 925 million won ($774,000) from May 2017 to June 2020. That compares with a gain of 2% in Busan and 15% in Daegu, where prices are only a third of those in the capital.

The government has expressed concern about excess liquidity flowing into the property market. Broad money supply -- known as M2 -- rose by 9.1% in April from a year earlier, the fastest pace since 2015, as the government expanded loans to struggling companies and handed out cash to families to relieve pandemic pain. The money supply has previously displayed a correlation with Seoul house price growth.

The BOK has cut interest rates by 75 basis points since the pandemic struck, delivering a corresponding decline in lending rates. While that’s a sign of effective monetary policy transmission, it’s a concern when property prices are still rising rapidly.

“There’s not much the central bank can do at this stage,” said Kim Jin-myoung, an economist at Hanwha Investment & Securities Co. in Seoul. “You can’t raise rates for the sole purpose of reining in property prices when the economy is still in a slump from the coronavirus.”

BOK Governor Lee Ju-yeol has repeatedly pledged to keep monetary policy accommodative until the economy recovers from the virus downturn. Minutes of the latest May interest rate decision showed some board members expressed concerns about housing market instability, while proceeding with a rate cut to help the economy.

Construction investment led South Korea’s economic expansion under the former administration, as interest-rates were cut and property regulations eased to buoy a then-stagnant property market. The trend has reversed in recent years, with tighter rules and a correction from the previous housing oversupply.

President Moon vowed late last year that the government wouldn’t use the property market as a means to boost growth. Yet the pandemic has deteriorated the outlook for the economy, which is now expected by analysts to contract this year for the first time since the late 1990s Asian financial crisis.

“The property curbs are negative for the construction investment outlook,” said An Young-jin, an economist at SK Securities. “But the government is willing to endure that as they place greater urgency on reining in the property market.”

©2020 Bloomberg L.P.

(Reuters) - U.S. equity funds in the week ended on Wednesday drew $609 million, the first inflow in four weeks, according to Lipper.

U.S. taxable bond funds attracted $12.6 billion, the 13th straight weekly inflow, while money market funds saw $4.7 billion come in, the first inflow in eight weeks, Lipper data showed on Thursday.