Codeforces 487C Prefix Product Sequence(逆元)

题目链接：Codeforces 487C Prefix Product Sequence

构造方式，从1开始，每次乘上i-1的逆元，再乘上i。

#include <cstdio>#include <cstring>#include <algorithm>using namespace std;typedef long long ll;const int maxn = 1e5 + 5;ll ans[maxn] = {0, 1};int pow_mod(ll x, int n, int mod) {ll ret = 1;while (n) {if (n&1)ret = ret * x % mod;x = x * x % mod;n >>= 1;}return ret;}int inv (int a, int n) {return pow_mod(a, n-2, n);}int main () {int n;scanf("%d", &n);if (n == 1)printf("YES\n1\n");else if (n == 4)printf("YES\n1\n3\n2\n4\n");else {for (int i = 2; i < n; i++) {ans[i] = inv(i, n);if (n % i == 0) {printf("NO\n");return 0;}}printf("YES\n1\n");for (int i = 2; i < n; i++)printf("%lld\n", ans[i-1] * i % n);printf("%d\n", n);}return 0;}