hihoCoder - 1586 Minimum 线段树模板

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cctype>
#include <sstream>
#include <cmath>

using namespace std;
const int inf =0x3f3f3f3f;
typedef long long LL;
const int MAXN = 200005;
struct Tree
{
int Max, Min;
int l, r ;
} tree[MAXN*4];
int a[MAXN];
int n;
void pushup(int k)
{
tree[k].Max =max(tree[k<<1].Max,tree[k<<1|1].Max);
tree[k].Min =min(tree[k<<1].Min,tree[k<<1|1].Min);
}
void build(int k, int l, int r)//建树的模板操作，通过递归和二分
{
tree[k].l  = l;
tree[k].r  = r;
if(l==r)
{
tree[k].Max=tree[k].Min=a[l];
return ;
}
int mid;
mid = (tree[k].l+tree[k].r)>>1;
build(k<<1, l, mid);
build(k<<1|1,mid+1,r);
pushup(k);
return ;
}
void update(int k, int pos, int c)
{
if(pos ==  tree[k].l && tree[k].r == pos)
{
tree[k].Max=tree[k].Min=c;
return ;
}
int mid=(tree[k].l+tree[k].r)>>1;
if(pos<=mid)
update(k<<1, pos, c);
else
update(k<<1|1, pos,c);
pushup(k);
}
LL Search1(int l, int r, int k)//query
{
int mid;
LL Max=-inf;
if(tree[k].l>=l&&tree[k].r<=r)
return Max = tree[k].Max;

mid = (tree[k].l+tree[k].r)>>1;
if(l<=mid)
Max=max(Max, Search1(l, r, k<<1));
if(r>mid)
Max=max(Max,Search1(l, r, k<<1|1));
return Max;
}
LL Search2(int l, int r, int k)//query
{
int mid;
LL Min=inf;
if(tree[k].l>=l&&tree[k].r<=r)
return tree[k].Min;
mid = (tree[k].l+tree[k].r)>>1;
if(l<=mid)
Min = min(Min, Search2(l, r, k<<1));
if(r>mid)
Min = min(Min, Search2(l, r, k<<1|1));
return Min;
}
int main()
{
int t, k;
scanf("%d", &t);
while(t--)
{
scanf("%d", &k);
n=1<<k;
for(int i=1;i<=n;++i)
scanf("%d", &a[i]);
build(1, 1, n);
//for(int i=1;i<=15;++i)
//printf("%d %lld %lld %lld %lld\n", i, tree[i].l, tree[i].r, tree[i].Max, tree[i].Min);
int q;
scanf("%d",&q);
while(q--)
{
int op ;
int x, y;
scanf("%d %d %d", &op, &x, &y);
x++;
if(op==2)
update(1, x, y);
else
{
LL Max, Min;
y++;
Max=Search1(x, y, 1);
Min=Search2(x, y, 1);
LL ans;
ans=min(Max*Max, Min*Min);
ans=min(Min*Max, ans);
//printf("%lld %lld\n", Max, Min);
printf("%lld\n", ans);
}
}
}
return 0;
}