为什么我的代码过不了

#include<bits/stdc++.h>
#define int long long
using namespace std;
signed main(){
	int n,p;
	cin>>n>>p;
	int a[5000005]={0};
	int c[5000005];
	for(int i=1;i<=n;i++) cin>>a[i], c[i]=a[i]-a[i-1];
	for(int i=1;i<=p;i++){
		int l,r,x;
		cin>>l>>r>>x;
		c[l]+=x;
		c[r+1]-=x;
	}
	int sum=0,minn=1000000;
	for(int i=1;i<=n;i++){
		sum+=c[i];
		if(sum<minn) minn=sum;
	}
	cout<<minn;
}