Acdream Multiplication 基础题

#include <cstdlib>
#include <cstdio>
#include <cstring>
#include <iostream>
#define MOD 1000000007
using namespace std;

int N;

long long sa[100005], sb[100005];

int cal(int x) {
return ((sa[x-1] % MOD) * (sb[x] - sb[x-1]) % MOD + (sb[x-1] % MOD) * (sa[x] - sa[x-1]) % MOD + (sa[x] - sa[x-1]) * (sb[x] - sb[x-1]) % MOD) % MOD;
}

int main() {
while (scanf("%d", &N) == 1) {
int c;
for (int i = 1; i <= N; ++i) {
scanf("%d", &c);
sa[i] = sa[i-1] + c;
}
for (int i = 1; i <= N; ++i) {
scanf("%d", &c);
sb[i] = sb[i-1] + c;
}
for (int i = 1; i <= N; ++i) {
printf(i == 1 ? "%d" : " %d", cal(i));
}
puts("");
}
return 0;
}