#include<stdio.h>int main(){ long long int que[2000001]; que[0] = 1; long long int a, b, c; scanf("%lld%lld%lld", &a, &b, &c); for (int i = 1; i <= 2000000; i++) { que[i] = (que[i - 1] * a + que[i - 1] % b) % c; } for (int i = 0; i <= 2000000; i++) { for (int k = 0; k < i; k++) { if (i <= 2000000) { if (que[k] == que[i]) { printf("%d", i); return 0; } } else { printf("-1"); return 0; } } }} 运行只通过4组数据……请欢迎指正！