线段树

#include<iostream>
#include<cstring>
#define Size 1000005
using namespace std;

struct Node{
    int l,r,mid;
    long long sum,tag;
}tree[Size];

void build(int num,int l,int r){//建树
    tree[num].l=l;
    tree[num].r=r;
    tree[num].mid=(l+r)/2;
    if(l<r){
        build(num*2,l,tree[num].mid);
        build(num*2+1,tree[num].mid+1,r);
    }
}

void single_insert(int num,int x,int d){//单点修改:元素x加上d 
    if(tree[num].l==tree[num].r)tree[num].sum+=d;
    else{
        if(x<=tree[num].l)single_insert(num*2,x,d);
        else single_insert(num*2+1,x,d);
        tree[num].sum=tree[num*2].sum+tree[num*2+1].sum;
    }
}

long long interval_query(int num,int l,int r){//区间查询
    long long ans=0;
    if(l<=tree[num].l&&r>=tree[num].r)return tree[num].sum;
    else{
        if(l<=tree[num].mid)ans+=interval_query(num*2,l,r);
        if(r>tree[num].mid)ans+=interval_query(num*2+1,l,r);
        return ans;
    }
}

void interval_update(int num,int l,int r,int d){//区间修改
   if(l<=tree[num].l&&r>=tree[num].r)tree[num].tag+=d; else{ if(l<=tree[num].mid)interval_update(num*2,l,r,d); if(r>tree[num].mid)interval_update(num*2+1,l,r,d); tree[num].sum= tree[num*2].sum+(tree[num*2].r-tree[num*2].l+1)*tree[num*2].tag+ tree[num*2+1].sum+(tree[num*2+1].r-tree[num*2+1].l+1)*tree[num*2+1].tag; } } int single_query(int num,int x){//单点查询 long long ans=0; if(tree[num].l==tree[num].r)return tree[num].sum+tree[num].tag; else{ tree[num].sum+=tree[num].tag; tree[num*2].tag+=tree[num].tag; tree[num*2+1].tag+=tree[num].tag; tree[num].tag=0; if(x<=tree[num].mid)return single_query(num*2,x); else return single_query(num*2+1,x); } } long long tag_interval_query(int num,int l,int r){//带tag的区间查询 long long ans=0; if(l<=tree[num].l&&r>=tree[num].r) return tree[num].sum+(tree[num].r-tree[num].l+1)*tree[num].tag; else{ if(tree[num].tag!=0){ tree[num].sum+=(tree[num].r-tree[num].l+1)*tree[num].tag; tree[num*2].tag+=tree[num].tag; tree[num*2+1].tag+=tree[num].tag; tree[num].tag=0; } if(l<=tree[num].mid)ans+=tag_interval_query(num*2,l,r); if(r>tree[num].mid)ans+=tag_interval_query(num*2+1,l,r); return ans; } } int main(){//codevs 1082 线段树练习3 memset(tree,0,sizeof(tree)); int n,a; cin>>n; build(1,1,n); for(int i=1;i<=n;i++){ cin>>a; interval_update(1,i,i,a); } int m,q,l,r,x; cin>>m; for(int i=1;i<=m;i++){ cin>>q; if(q==1){ cin>>l>>r>>x; interval_update(1,l,r,x); } else{ cin>>l>>r; cout<<tag_interval_query(1,l,r)<<endl; } } }
原文地址:https://www.cnblogs.com/FuTaimeng/p/5642318.html