多校联合第一场 数学

思路是维护数列的前缀积和后缀积，每次取对应的位置相乘即可。

#include <cstdio>
#include <cstring>
using namespace std;

const int N = 111111;
const int MOD = 1000000007;

int n, a[N], prefix[N], suffix[N];

int multiply(int a, int b) {
    return (long long)a * b % MOD;
}

int main() {
    while (scanf("%d", &n) == 1 && n) {
		for (int i = 1; i <= n; ++ i) {
		    scanf("%d", a + i);
		}
		prefix[0] = 1;
		for (int i = 1; i <= n; ++ i) {
		    prefix[i] = multiply(prefix[i - 1], a[i]);
		}
		suffix[n + 1] = 1;
		for (int i = n; i >= 1; -- i) {
		    suffix[i] = multiply(suffix[i + 1], a[i]);
		}
		for (int i = 1; i <= n; ++ i) {
		    printf("%d%c", multiply(prefix[i - 1], suffix[i + 1]), i == n? '\n': ' ');
	    }
	}
    return 0;
}