【codevs1081】线段树练习2

problem

solution

codes

#include<iostream>
using namespace std;
const int maxn = 100010;
#define lch p<<1
#define rch p<<1|1
struct node{
    int val, addmark;
}sgt[maxn<<2];
void pushdown(int p, int l, int r){
    if(!sgt[p].addmark)return;
    int t = sgt[p].addmark, m=l+r>>1;
    sgt[lch].addmark += t;
    sgt[rch].addmark += t;
    sgt[lch].val += t*(m-l+1);
    sgt[rch].val += t*(r-m);
    sgt[p].addmark = 0;
}
void update(int p, int l, int r, int ql, int qr, int v){
    if(l>qr || r<ql)return ;
    if(ql<=l && r<=qr){
        sgt[p].val += v*(r-l+1);
        sgt[p].addmark += v;
        return ;
    }
    int m = l+r>>1;
    if(ql<=m)update(lch,l,m,ql,qr,v);
    if(qr>m)update(rch,m+1,r,ql,qr,v);
    sgt[p].val = sgt[lch].val+sgt[rch].val;
}
int query(int p, int l, int r, int ql, int qr){
    if(ql<=l && r<=qr)return sgt[p].val;
    pushdown(p,l,r);
    int m = l+r>>1, ans = 0;
    if(ql<=m)ans += query(lch,l,m,ql,qr);
    if(qr>m)ans += query(rch,m+1,r,ql,qr);
    return ans;
}
int main(){
    int n, m;
    cin>>n;
    for(int i = 1; i <= n; i++){
        int x;  cin>>x;  update(1,1,n,i,i,x);
    }
    cin>>m;
    for(int i = 1; i <= m; i++){
        int op, x, y, k;
        cin>>op;
        if(op == 1){
            cin>>x>>y>>k;
            update(1,1,n,x,y,k);
        }else{
            cin>>x;
            cout<<query(1,1,n,x,x)<<"\n";
        }
    }
    return 0;
}