差分写法60分WA （麻烦各位神犇帮我看看）

#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int N = 6 * int(1e6);
int n, p, ans = 1e9;
int d[N], a[N];

int main() {
    cin >> n >> p;
    for (int i = 1; i <= n; i++) {
        cin >> d[i];
        d[i] = d[i] - d[i - 1];
    }
    for (int i = 1; i <= p; i++) {
        int x, y, z;
        cin >> x >> y >> z;
        d[x] += z;
        d[y + 1] -= z;
    }
    for (int i = 1; i <= n; i++) {
        a[i] = d[i] + a[i - 1];
        ans = min(ans, a[i]);
    }

    cout << ans;
    return 0;
}