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欧拉函数定义：设n 为正整数，则1，2......,n中与n互质的整数个数记作f(n)。 1.1 若n为素数，f(n)=n-1; 1.2 整数n=p*q，p，q为不同素数，则f(n)=f(p)*f(q)=(p-1)*(q-1) 1.3 n=p^a*q^b,f(n)=f(p^a)*f(q^b)=n*( 阅读全文
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Scales Time Limit: 1000MS Memory Limit: 65536K Total Submissions: 3148 Accepted: 851 Description Farmer John has a balance for weighing the cows. He a 阅读全文
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River Hopscotch Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 15273 Accepted: 6465 Description Every year the cows hold an event featurin 阅读全文
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Description Farmer John's N (1 <= N <= 50,000) cows (numbered 1..N) are planning to run away and join the circus. Their hoofed feet prevent them from 阅读全文
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A natural number, N, that can be written as the sum and product of a given set of at least two natural numbers, {a1, a2, ... , ak} is called a product 阅读全文