POJ2407Relatives(欧拉函数入门题目）

#include <iostream>#include <cstdio>#include <cstring>using namespace std;//Accepted164K0MSC++472Bint work(int n) {    int rea = n;    for(int i = 2; i*i<=n; i++) {        if(n%i == 0) {            rea = rea - rea/i;            while(n%i==0) { n /= i; }        }    }    if(n>1) { rea = rea - rea/n ;}      return rea;}int main(){    int n;    while(scanf("%d", &n) && n) {        int res = work(n);        printf("%d\n", res);    }    return 0;}