80分求助!c++!

#include<iostream>
const int N=5e6+200+1;
const int M=5e6+1;
int n,p,minn=N,chengji[M],x,y,z;
int main()
{
    scanf("%d%d",&n,&p);
    for(int i=1;i<=n;i++){
        scanf("%d",&chengji[i]);
    }
    for(int i=1;i<=p;i++){
        scanf("%d%d%d",&x,&y,&z);
        for(int j=x-1;j<=y-1;j++){
            chengji[j]+=z;
        }
    }
    for(int i=1;i<=n;i++){
        if(minn>chengji[i]){
            minn=chengji[i];
        }
    }
    printf("%d",minn);
    return 0;  
}

~~最后一个测试点TLE了! ~~