Problem:
Range Minimum Query (RMQ)

Write a program which manipulates a sequence A = {a0, a1, . . . , an-1} with the following operations:

find(s, t): report the minimum element in as, as+1, . . . ,at.

update(i, x): change ai to x.

Note that the initial values of ai (i = 0, 1, . . . , n−1) are 231-1.

Input

n q
com0 x0 y0
com1 x1 y1
...
comq−1 xq−1 yq−1

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, q queries are given where com represents the type of queries. '0' denotes update(xi, yi) and '1' denotes find(xi, yi).

Output

For each find operation, print the minimum element.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

If comi is 0, then 0 ≤ xi < n, 0 ≤ yi < 231-1.

If comi is 1, then 0 ≤ xi < n, 0 ≤ yi < n.

Sample Input 1

3 5
0 0 1
0 1 2
0 2 3
1 0 2
1 1 2

Sample Output 1

1
2

Sample Input 2

1 3
1 0 0
0 0 5
1 0 0

Sample Output 2

2147483647
5

Solution in C (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#define ll long long
#define rep(i,l,r)for(ll i=(l);i<(r);i++)
#define min(p,q)((p)<(q)?(p):(q))


//セグ木ここから
//*
//↓ここを変える
typedef struct atai{ll a;}atai;
atai xx(atai x,atai y){
	atai r;
	r.a=min(x.a,y.a);//min
	return r;
}
atai aid={(1LL<<31)-1};
//↑ここを変える

int segNUM;
atai *segN,*seg;
void seguse(int n){
	segN=(atai*)calloc(2*n,sizeof(atai));
	segNUM=n;
	seg=segN+segNUM;
	rep(i,1,2*segNUM)segN[i]=aid;
}
//seg[]に値を与えてから初期化
void seginit(){for(int node=segNUM-1;node;node--)segN[node]=xx(segN[node*2],segN[node*2+1]);}
void segupdate(int node,atai x){
	//seg[node]をxに更新
	node+=segNUM;
	segN[node]=x;
	while(node/=2)segN[node]=xx(segN[node*2],segN[node*2+1]);
}

atai segcalcsub(int l,int r,int k,int cl,int cr){
	if(l>=r)return aid;
	//完全に含むとき
	if(l<=cl&&cr<=r)return segN[k];

	int cm=(cl+cr)/2;
	//左側だけ
	if(r<=cm)return segcalcsub(l,r,2*k  ,cl,cm);
	//右側だけ
	if(cm<=l)return segcalcsub(l,r,2*k+1,cm,cr);
	//両方
	return xx(segcalcsub(l,r,2*k,cl,cm),segcalcsub(l,r,2*k+1,cm,cr));
}
atai segcalc(int l,int r){return segcalcsub(l,r,1,0,segNUM);}
//セグ木ここまで
//*/


int main(){
	int n,q;
	scanf("%d%d",&n,&q);
	seguse(1<<17);
	while(q--){
		int t,x,y;
		scanf("%d%d%d",&t,&x,&y);
		if(t)printf("%lld\n",segcalc(x,y+1).a);
		else{
			atai a={y};
			segupdate(x,a);
		}
	}
}