Recommended sequence ACM

1. Zhejiang University Online judge (zoj)

Http://acm.zju.edu.cn

The earliest and most famous OJ in China, with many experts doing the above. The feature is that the data is relatively difficult to drill, and there are often boundary data that you don't think of, which can test the comprehensiveness of thinking. Now I am mainly doing this on OJ.

Smooth Network

Peking University Online judge (poj)

Http://acm.pku.edu.cn/JudgeOnline/

It was established later, but the question was quickly added. Now the number of questions is comparable to that of zoj, which is characterized by a large number of online competitions and weak data compared with zoj. Sometimes the same questions are the same program, on zoj, WA and poj will be able to AC

2. Spanish Valladolid University Online judge (ultraviolet)

Http://online-judge.uva.es/problemset/

The world's largest and most famous OJ, with a huge number of questions and a huge variety of miscellaneous, data is also very tricky, and top experts all over the world are on top. It is said that if you can have more than one thousand questions on the AC, even if you send a resume to IBM or Microsoft, it will never disappoint you.

Russian Ural University Online judge (Ural)

Http://acm.timus.ru/

It is also an old-fashioned OJ. There are not many questions, but the question is classic.

3. usaco online judge (usaco)

Http://ace.delos.com/usacogate

The training website of the National Computer Olympics (usaco) is characterized by the fact that it can continue to do so after it completes a close test. What is different from the previous OJ is that the test data can be seen, and after the test is done, you can see the standard answers, so if you can't find the reason for the above OJ's total wa at the beginning, you can try to do it here to see where the test data is generally overcast to you.