【luogu P3372 线段树1】 模板

线段树的模板题

题目链接：https://www.luogu.org/problemnew/show/P3372

update区间修改，query区间求和

#include <iostream>
#include <cstdio>
#include <algorithm>
#define ll long long
#define lson left, mid, rt<<1
#define rson mid+1, right, rt<<1|1
using namespace std;
const int maxn = 100000;
ll n, m, ans[maxn<<2],lazy[maxn<<2],tot=0,re[maxn<<2];
void PushUP(ll rt)
{
    ans[rt] = ans[rt<<1] + ans[rt<<1|1];
}
void build(ll left, ll right, ll rt)
{
    if(left == right)
    {
        cin>>ans[rt];
        return;
    }
    ll mid = (left + right)>>1;
    build(lson);
    build(rson);
    PushUP(rt);
}

void PushDOWN(ll rt, ll mid, ll left, ll right)
{
    if(lazy[rt])
    {
        lazy[rt<<1]+=lazy[rt];
        lazy[rt<<1|1]+=lazy[rt];
        ans[rt<<1]+=(mid-left+1)*lazy[rt];
        ans[rt<<1|1]+=(right-mid)*lazy[rt];
        lazy[rt]=0;
    }
}
ll query(ll l, ll r, ll left, ll right, ll rt)
{
    ll res = 0;
    if(l<=left&&r>=right)
    {
        return ans[rt];
    }
    ll mid = (left + right)>>1;
    PushDOWN(rt,mid,left,right);
    if(l<=mid) res += query(l,r,lson);
    if(r>mid) res += query(l,r,rson);
    return res;
}
void update(ll l, ll r, ll add, ll left, ll right, ll rt)
{
    if(l<=left&&r>=right)
    {
        lazy[rt]+=add;
        ans[rt]+=add*(right-left+1);
        return;
    }    
    ll mid = (left+right)>>1;
    PushDOWN(rt,mid,left,right);
    if(l<=mid) update(l,r,add,lson);
    if(r>mid)  update(l,r,add,rson);
    PushUP(rt);
}

int main()
{
    cin.sync_with_stdio(false);
    cin>>n>>m;
    ll p,x,y,k;
    build(1,n,1);
    while(m--)
    {
        cin>>p;
        if(p==1)
        {
            cin>>x>>y>>k; update(x,y,k,1,n,1);
        }
        if(p==2)
        {
            tot++;
            cin>>x>>y;    cout<<query(x,y,1,n,1);
        }
    }
    return 0;
}