线段树 区间更新 区间求和以及最值

<pre name="code" class="cpp">#include <iostream>
#include <string.h>
#include <algorithm>
#include <stdio.h>
#include <math.h>
#include <queue>
#define MAXN 100010
#define inf 0x3f3f3f3f

using namespace std;

struct node{
int l,r;//区间[l,r]
int add;//区间的延时标记
int sum;//区间和
int mx; //区间最大值
int mn; //区间最小值
}tree[MAXN<<2];//一定要开到4倍多的空间

void pushup(int index){
tree[index].sum = tree[index<<1].sum+tree[index<<1|1].sum;
tree[index].mx = max(tree[index<<1].mx,tree[index<<1|1].mx);
tree[index].mn = min(tree[index<<1].mn,tree[index<<1|1].mn);
}
void pushdown(int index){
//说明该区间之前更新过
//要想更新该区间下面的子区间，就要把上次更新该区间的值向下更新
if(tree[index].add > 0){
//替换原来的值
/*
tree[index<<1].sum = (tree[index<<1].r-tree[index<<1].l+1)*tree[index].add;
tree[index<<1|1].sum = (tree[index<<1|1].r-tree[index<<1|1].l+1)*tree[index].add;
tree[index<<1].mx = tree[index].add;
tree[index<<1|1].mx = tree[index].add;
tree[index<<1].mn = tree[index].add;
tree[index<<1|1].mn = tree[index].add;
tree[index<<1].add = tree[index].add;
tree[index<<1|1].add = tree[index].add;
tree[index].add = 0;*/
//在原来的值的基础上加上val

tree[index<<1].sum += (tree[index<<1].r-tree[index<<1].l+1)*tree[index].add;
tree[index<<1|1].sum +=(tree[index<<1|1].r-tree[index<<1|1].l+1)*tree[index].add;
tree[index<<1].mx += tree[index].add;
tree[index<<1|1].mx += tree[index].add;
tree[index<<1].mn += tree[index].add;
tree[index<<1|1].mn += tree[index].add;
tree[index<<1].add += tree[index].add;
tree[index<<1|1].add += tree[index].add;
tree[index].add = 0;

}
}
void build(int l,int r,int index){
tree[index].l = l;
tree[index].r = r;
tree[index].add = 0;//刚开始一定要清0
if(l == r){
scanf("%d",&tree[index].sum);
tree[index].mn = tree[index].mx = tree[index].sum;
return ;
}
int mid = (l+r)>>1;
build(l,mid,index<<1);
build(mid+1,r,index<<1|1);
pushup(index);
}
void updata(int l,int r,int index,int val){
if(l <= tree[index].l && r >= tree[index].r){
/*把原来的值替换成val,因为该区间有tree[index].r-tree[index].l+1
个数，所以区间和 以及 最值为：
*/
/*tree[index].sum = (tree[index].r-tree[index].l+1)*val;
tree[index].mn = val;
tree[index].mx = val;
tree[index].add = val;//延时标记*/
//在原来的值的基础上加上val,因为该区间有tree[index].r-tree[index].l+1
//个数，所以区间和 以及 最值为：
tree[index].sum += (tree[index].r-tree[index].l+1)*val;
tree[index].mn += val;
tree[index].mx += val;
tree[index].add += val;//延时标记

return ;
}
pushdown(index);
int mid = (tree[index].l+tree[index].r)>>1;
if(l <= mid){
updata(l,r,index<<1,val);
}
if(r > mid){
updata(l,r,index<<1|1,val);
}
pushup(index);
}
int query(int l,int r,int index){
if(l <= tree[index].l && r >= tree[index].r){
//return tree[index].sum;
return tree[index].mx;
//return tree[index].mn;
}
pushdown(index);
int mid = (tree[index].l+tree[index].r)>>1;
int ans = 0;
int Max = 0;
int Min = inf;
if(l <= mid){
ans += query(l,r,index<<1);
Max = max(query(l,r,index<<1),Max);
Min = min(query(l,r,index<<1),Min);
}
if(r > mid){
ans += query(l,r,index<<1|1);
Max = max(query(l,r,index<<1|1),Max);
Min = min(query(l,r,index<<1|1),Min);
}
//return ans;
return Max;
//return Min;
}
int main()
{
int n,m,q,x,y,z;
while(~scanf("%d%d",&n,&m)){
build(1,n,1);
while(m--){
scanf("%d",&q);
if(q == 1){
cout<<"查询:(x,y)"<<endl;
scanf("%d %d",&x,&y);
cout<<query(x,y,1)<<endl;
}
else{
cout<<"更新(x,y)为z："<<endl;
scanf("%d %d %d",&x,&y,&z);
updata(x,y,1,z);
for(int i = 1; i <= n; ++i){
printf("a[%d] = %d\n",i,query(i,i,1));
}
}
}
}
return 0;
}