ACM-ICPC国际大学生程序设计竞赛北京赛区(2017)网络赛 I.Minimum(线段树_单点修改，查询区间最大最少值)

题目链接：Minimum

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<queue>
#include<stack>
#include<vector>
#include<cmath>
#include<map>
#include<set>
#include<cstdlib>
#define mem(a,b) memset(a,b,sizeof(a))
#define INF 0x7fffffff
typedef long long ll;
using namespace std;
const int maxn = (1 << 17) + 10;
const int maxNode = maxn << 2;

int MAX[maxNode];
int MIN[maxNode];

void pushUpMax(int rt){
    MAX[rt] = max(MAX[rt<<1],MAX[rt<<1|1]);
}
void pushUpMin(int rt){
    MIN[rt] = min(MIN[rt<<1],MIN[rt<<1|1]);
}

void build(int rt,int l,int r){
    if(l == r){
        scanf("%d",&MAX[rt]);
        MIN[rt] = MAX[rt];
        return;
    }
    int mid = (l+r)/2;
    build(rt<<1,l,mid);
    build(rt<<1|1,mid+1,r);
    pushUpMax(rt);
    pushUpMin(rt);
}

int queryMin(int rt,int l,int r,int L,int R){
    if(l <= L && R <= r){
        return MIN[rt];
    }
    int mid = (L+R)/2;
    int ans = maxn;
    if(l <= mid) ans = min(ans,queryMin(rt<<1,l,r,L,mid));
    if(r > mid) ans = min(ans,queryMin(rt<<1|1,l,r,mid+1,R));
    return ans;
}

int queryMax(int rt,int l,int r,int L,int R){
    if(l <= L && R <= r){
        return MAX[rt];
    }
    int mid = (L+R)/2;
    int ans = -maxn;
    if(l <= mid){
        ans = max(ans,queryMax(rt<<1,l,r,L,mid));
    }
    if(r > mid){
        ans = max(ans,queryMax(rt<<1|1,l,r,mid+1,R));
    }
    return ans;
}

void update(int rt,int pos,int val,int L,int R){
    if(L == R){
        MAX[rt] = MIN[rt] = val;
        return;
    }
    int mid = (L+R)/2;
    if(pos <= mid) update(rt<<1,pos,val,L,mid);
    else update(rt<<1|1,pos,val,mid+1,R);
    pushUpMax(rt);
    pushUpMin(rt);
}

int main(){
    int T,n,m;
    scanf("%d",&T);
    while(T--){
        scanf("%d",&n);
        n = (1 << n);
        build(1,1,n);
        scanf("%d",&m);
        while(m--){
            int a,b,ch;
            scanf("%d%d%d",&ch,&a,&b);
            if(ch == 1){
                ll ans;
                int minn = queryMin(1,a+1,b+1,1,n);
                int maxx = queryMax(1,a+1,b+1,1,n);
                if(minn == 0 || maxx == 0) puts("0");
                else if(minn > 0){
                    ans = (ll)minn * minn;
                }else if(maxx < 0){
                    ans = (ll)maxx * maxx;
                }else{
                    ans = (ll)maxx * minn;
                }
                printf("%lld\n",ans);

            }else{
                update(1,a+1,b,1,n);
            }
        }

    }

    return 0;
}