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The greatest common divisor GCD(a,b) of two positive integers a and b,sometimes written (a,b),is the largest divisor common to a and b,For example,(1, 阅读全文
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Fernando won a compass for his birthday, and now his favorite hobby is drawing stars: first, he marks N points on a circumference, dividing it into N e 阅读全文
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Given a positive integer N, your task is to calculate the sum of the positive integers less than N which are not coprime to N. A is said to be coprime 阅读全文
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原题链接：http://codeforces.com/problemset/problem/320/B 之前自己做的时候一直读不懂题意，看了大佬的博客才知道是用dfs写，一道暴力搜索大水题https://www.cnblogs.com/windysai/p/3531473.html 题目意思：有两种 阅读全文