Enhanced tree array luogu3368

The violent tree array is 30 points, what should I do?

Knowledge point review

in difference array

After the beginning and the end have changed the value

Find his prefix and find that all numbers in the interval change

Then we do differential tree array

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#include<iostream>
#include<cstdio>
using namespace std;
int n,m;
int c[501010];
int lowbit(int x){
    return x&-x; 
}
void update(int i,int x){
    while(i <= n){
        c[i] += x;
        i += lowbit(i);    
    }
}
int sum(int x)
{
    int sum = 0;
    while(x){
        sum += c[x];
        x -= lowbit(x);    
    }
    return sum;
}
intmain ()
{
    cin >> n >> m;
    int x, y, z, k; 
    for(int i = 1;i <= n;++ i){
        cin >> x; 
        update(i,x),update(i+1,-x); 
    }
    while(m-- ){
        cin >> z;
        if(z == 2){
            cin>>x;
             cout<<sum(x)<<"\n";
        }else{
               cin >> x >> y >> k;
               update(x, k);update(y+1, -k);
        }
    }
    return 0;
}