POJ 3468 A Simple Problem with Integers 线段树

线段树模版题。

贴个代码。

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <string>
#include <cmath>
#include <cstring>
#include <queue>
#include <set>
#include <vector>
#include <stack>
#include <map>
#include <iomanip>
#define PI acos(-1.0)
#define Max 100005
#define inf 1<<28
using namespace std;

struct kdq
{
int l,r;
long long num,add;//add为每次更新是增加的值
} tree[Max*4];
int a[Max];
int n,m;
long long ans;
void build_tree(int l,int r,int u)//建树
{
tree[u].l=l,tree[u].r=r;
tree[u].add=0;
if(l==r)
{
tree[u].num=a[l];
return ;
}
int mid=(l+r)/2;
build_tree(l,mid,u<<1);
build_tree(mid+1,r,(u<<1)+1);
tree[u].num=tree[u<<1].num+tree[(u<<1)+1].num;
}
void query(int left,int right,int u)//询问
{
if(left>tree[u].r||right<tree[u].l)//位于树外
{
return ;
}
if(left<=tree[u].l&&right>=tree[u].r)//包含这个节点
{
ans+=tree[u].num;
return ;
}
if(tree[u].add)//更新树
{
tree[u<<1].num += (tree[u<<1].r-tree[u<<1].l+1)*tree[u].add;
tree[u<<1].add += tree[u].add;
tree[(u<<1)+1].num += (tree[(u<<1)+1].r-tree[(u<<1)+1].l+1)*tree[u].add;
tree[(u<<1)+1].add += tree[u].add;
tree[u].add = 0;
}
query(left,right,u<<1);
query(left,right,(u<<1)+1);
tree[u].num=tree[u<<1].num+tree[(u<<1)+1].num;
}
void updata(int left,int right,int u,int k)//更新
{
if(left>tree[u].r||right<tree[u].l)
{
return ;
}
if(left<=tree[u].l&&right>=tree[u].r)
{
tree[u].num+=(tree[u].r-tree[u].l+1)*k;
tree[u].add+=k;
return ;
}
if(tree[u].add)
{
tree[u<<1].num += (tree[u<<1].r-tree[u<<1].l+1)*tree[u].add;
tree[u<<1].add += tree[u].add;
tree[(u<<1)+1].num += (tree[(u<<1)+1].r-tree[(u<<1)+1].l+1)*tree[u].add;
tree[(u<<1)+1].add += tree[u].add;
tree[u].add = 0;
}
updata(left,right,u<<1,k);
updata(left,right,(u<<1)+1,k);
tree[u].num=tree[u<<1].num+tree[(u<<1)+1].num;
}
int main()
{
int i,j,k,l;
while(scanf("%d%d",&n,&m)!=EOF)
{
char op[1];
int x,y;
for(i=1; i<=n; i++)
scanf("%d",&a[i]);
build_tree(1,n,1);
while(m--)
{
scanf("%s",op);
if(op[0]=='Q')
{
ans=0;
scanf("%d%d",&x,&y);
query(x,y,1);
printf("%I64d\n",ans);
}
else
{
scanf("%d%d%d",&x,&y,&k);
updata(x,y,1,k);
}
}
}
return 0;
}