算法模板 线段树

区间修改 查询等 详见注释

#include<cstdio>
#include<cstdlib>
#include<iostream>
#include<algorithm>
#include<cstring>
#include<cmath>
#include<queue>
#include<set>
#include<string>
#include<stack>
#include<map>
using namespace std;
const int INF=0x3f3f3f3f;
typedef pair<int, int> P;
typedef long long ll;
#define fi first/
#define se scond
#define me(x) memset(x, -1, sizeof(x))
#define mem(x) memset(x, 0, sizeof(x))
#define sc(x) scanf("%lld", &x)
#define sca(x,y) scanf("%lld%lld", &x, &y)
#define pr(x) printf("%lld
", x)
#define pri(x) printf("%lld ", x)
#define fo(i,n) for(i=0; i<n; i++)
#define rfo(i,n) for(i=n-1; i>=0; i--)
#define N 2000000 + 5

ll tree[N*4];
ll lazy[N*4];
void push_up(ll rt)
{
    tree[rt]=tree[rt<<1] + tree[rt<<1|1];
}
//向下传lazy标记
void push_down(ll rt, ll len)
{
    lazy[rt<<1] += lazy[rt]; //左右子树标记更新
    lazy[rt<<1|1] += lazy[rt];
    //左右子树数值更新
    tree[rt<<1] += (len-(len>>1)) * lazy[rt];//奇数长度 左子树更长
    tree[rt<<1|1] += (len>>1) * lazy[rt];

    lazy[rt]=0;//取消该节点标记
}
/*
//建树
           1
     2           3
   4    5      6     7
  8 9        12 13
e.g.  n=6 data:1 2 3 4 5 6
      tree[8]=1
      tree[9]=2
      tree[5]=3
      tree[12]=4
      tree[13]=5
      tree[7]=6
*/
void build(ll rt, ll l, ll r)
{
    if(l==r)
    {
        cin>>tree[rt];
        return ;
    }
    ll m=r+l >> 1;
    build(rt<<1, l, m);
    build(rt<<1|1, m+1, r);
    push_up(rt); //向上更新父节点
}
//单点更新
/*
void update(ll rt, ll l, ll r, ll p, ll x, ll k)
{
    if(l==r)
    {
        if(k==1)
        tree[rt]+=x;
        else tree[rt]-=x;
        return ;
    }
    ll m = l+r >>1;
    if(p<=m) update(rt<<1, l, m, p, x, k);
    else update(rt<<1|1, m+1, r, p, x, k);
    push_up(rt);
}
*/
//区间更新
void Update(ll rt, ll l, ll r, ll p, ll L, ll R)
{
    if(L<=l && r<=R) //缩到指定区间 更新
    {
        tree[rt]+=(r-l+1)*p;
        lazy[rt]+=p; //更新标记
        return ;
    }
    if(lazy[rt]) push_down(rt, r-l+1); //及时下传标记
    ll m= r+l >> 1;
    if(L<=m) Update(rt<<1, l, m, p, L, R);
    if(R>m) Update(rt<<1|1, m+1, r, p, L, R);
    push_up(rt);
}
//区间查询
ll query(ll rt, ll l, ll r, ll L, ll R)
{
    if(L<=l && r<=R)
    {
        return tree[rt];
    }
    ll s=0;
    if(lazy[rt]) push_down(rt,r-l+1); //及时下传标记
    ll m = r+l >>1;
    if(L<=m) s+=query(rt<<1, l, m, L, R);
    if(R>m) s+=query(rt<<1|1, m+1, r, L, R);
    return s;
}
int main()
{
    ll i, j , k;
    ll n, m;
    ll L, R, p;
    cin>>n>>m;

    build(1,1,n);

    //for(i=1; i<=20; i++) cout<<i<<' '<<tree[i]<<endl;

    fo(i,m)
    {
        char c;
        cin>>c;
        if(c=='Q')
        {
            cin>>L>>R;
            if(L>R) swap(L,R);
            k=query(1,1,n,L,R);
            cout<<k<<endl;
        }
        else if(c=='C')
        {
            cin>>L>>R;
            if(L>R) swap(L,R);
            cin>>p;
            Update(1,1,n,p,L,R);
        }
    }
}