XDOJ_1013_线段更新求和

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

int a[100005],sum[100005];

int main()
{
    int n,m,l,r,k;
    while(~scanf("%d",&n))
    {
        long long summ = 0;
        memset(sum,0,sizeof(sum));
        for(int i = 1;i <= n;i++)    scanf("%d",&a[i]);
        scanf("%d",&m);
        for(int i = 1;i <= m;i++)
        {
            scanf("%d%d%d",&l,&r,&k);
            sum[l+1] -= k;
            sum[r+1] += k;
        }
        for(int i = 1;i <= n;i++)
        {
            sum[i] += sum[i-1];
            a[i] += sum[i];
            summ += a[i];
        }
        int ave = summ/n;
        for(int i = 1;i <= n;i++)    a[i] -= ave;
        summ = 0;
        for(int i = 1;i <= n;i++)    summ += (long long)a[i]*a[i];
        printf("%lld\n",summ);
    }
    return 0;
}