线段树-区间更新-区间和模板

线段树-区间更新-区间和模板

代码：

#include <iostream>
using namespace std;

const int MAX_N = 10010;
int s[4 * MAX_N],col[4 * MAX_N];

void up(int p){
    s[p] = s[p * 2] + s[p * 2 + 1];
}

void down(int p, int l, int r){
    if(col[p]){
        int mid = (l + r) / 2;
        s[p * 2] += col[p] * (mid - l + 1);
        s[p * 2 + 1] += col[p] * (r - mid);
        col[p * 2] += col[p];
        col[p * 2 + 1] += col[p];
        col[p] = 0;
    }
}

void modify(int p,int l,int r,int x,int y,int c){
    if(x <= l && r <=y){
		s[p] += (r - l + 1) * c;
        col[p] += c;
        return;
    }
    down(p, l, r);
    int mid = (l + r)/2;
    if(x <= mid){
        modify(p * 2, l, mid, x, y, c);
    }
    if(y > mid){
        modify(p * 2 + 1, mid + 1,r,x,y,c);
    }
    up(p);
}

int query(int p,int l,int r,int x,int y){
	if(x <= l && r <= y){
        return s[p];
    }
    down(p,l,r);
    int mid = (l + r) / 2, res = 0;
    if(x <= mid){
		res += query(p * 2, l,mid,x,y);
    }
    if(y > mid){
        res += query(p * 2 + 1,mid + 1,r,x,y);
    }
    return res;
}

int main() {
	int n;
    cin>>n;
    for(int i=1;i<=n;++i){
        int d;
        cin>>d;
        modify(1,1,n,i,i,d);
    }
    int q;
    cin>>q;
    while(q--){
		int d,x,y,c;
        cin>>d>>x>>y;
        if(d == 0){
			cin >> c;
            modify(1,1,n,x,y,c);
        }else{
            cout<< query(1,1,n,x,y)<<endl;
        }
    }
    return 0;
}