【洛谷1592】【模板】template 线段树 线段树裸题

[code]#include<cstdio>
#include<iostream>
#include<cstring>
#include<algorithm>
using namespace std;

const int SIZE=500010;

typedef long long LL;

struct seg{
    int l,r;
    LL sum,add;
}tree[SIZE*4];

void update(int p)
{
    tree[p].sum=tree[p<<1].sum+tree[p<<1|1].sum;
}

void build(int p,int l,int r)
{
    tree[p].l=l; tree[p].r=r;
    if(l==r)
    {
        tree[p].sum=tree[p].add=0;
        return ;
    }
    int mid=(l+r)>>1;
    build(p<<1,l,mid);
    build(p<<1|1,mid+1,r);
    update(p);
}

void spread(int p)
{
    if(tree[p].add)
    {
        LL d=tree[p].add;
        tree[p<<1].sum+=d*(tree[p<<1].r-tree[p<<1].l+1);
        tree[p<<1|1].sum+=d*(tree[p<<1|1].r-tree[p<<1|1].l+1);
        tree[p<<1].add+=d;
        tree[p<<1|1].add+=d;
        tree[p].add=0;
    }
}

void change(int p,int l,int r,LL d)
{
    if(l<=tree[p].l&&tree[p].r<=r)
    {
        tree[p].add+=d;
        tree[p].sum+=d*(tree[p].r-tree[p].l+1);
        return ;
    }
    spread(p);
    int mid=(tree[p].l+tree[p].r)>>1;
    if(l<=mid) change(p<<1,l,r,d);
    if(mid<r) change(p<<1|1,l,r,d);
    update(p); 
}

LL ask(int p,int l,int r)
{
    if(l<=tree[p].l&&tree[p].r<=r)
    {
        return tree[p].sum;
    }
    spread(p);
    int mid=(tree[p].l+tree[p].r)>>1;
    LL ans=0;
    if(l<=mid) ans+=ask(p<<1,l,r);
    if(mid<r) ans+=ask(p<<1|1,l,r);
    return ans;
}

void scanf(int &n)
{
    n=0;
    bool flag=0;
    char a=getchar();
    while(a<'0'||a>'9') {if(a=='-') flag=1;a=getchar();}
    while(a>='0'&&a<='9') n=(n<<3)+(n<<1)+a-'0',a=getchar();
    if(flag) n=-n;
}

void scanf(LL &n)
{
    n=0;
    bool flag=0;
    char a=getchar();
    while(a<'0'||a>'9') {if(a=='-') flag=1;a=getchar();}
    while(a>='0'&&a<='9') n=(n<<3)+(n<<1)+a-'0',a=getchar();
    if(flag) n=-n;
}

int main()
{
    int n,m;
    scanf(n); scanf(m);
    build(1,1,n);
    while(m--)
    {
        LL s;
        scanf(s);
        switch(s)
        {
            case 1:
                int l,r;
                scanf(l);scanf(r);
                printf("%lld\n",ask(1,l,r));
                break;
            case 2:
                int a,b;
                LL c;
                scanf(a); scanf(b); scanf(c);
                change(1,a,b,c);
                break;
        }       
    }
    return 0;
}