Problem:
RMQ and RUQ

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

update(s, t, x): change as, as+1, ..., at to x.

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

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

Input

n q
query1
query2
:
queryq

In the first line, n (the number of elements in A) and q (the number of queries) are given. Then, ith query queryi is given in the following format:

0 s t x

or

1 s t

The first digit represents the type of the query. '0' denotes update(s, t, x) and '1' denotes find(s, t).

Output

For each find operation, print the minimum value.

Constraints

1 ≤ n ≤ 100000

1 ≤ q ≤ 100000

0 ≤ s ≤ t < n

0 ≤ x < 231−1

Sample Input 1

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

Sample Output 1

1
2

Sample Input 2

1 3
1 0 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))



//*
//遅延セグ木ここから
//↓ここを変える
typedef struct sayouso{ll a,b;}sayouso;
typedef struct atai{ll a;}atai;
//↑ここを変える

typedef struct node{sayouso T;atai x;}node;
node *lsegN,*lseg;
ll lsegNUM,lsegk;

//↓ここから変える
sayouso sid={1,0};
atai aid={(1LL<<31)-1};
atai xx(atai x,atai y){
	atai ret;
	ret.a=min(x.a,y.a);
	return ret;
}
atai Tx(sayouso T,atai x){
	atai ret;
	ret.a=T.a*x.a+T.b;
	return ret;
}
sayouso TT(sayouso S,sayouso T){
	sayouso ret;
	ret.a=S.a*T.a;
	ret.b=S.b+S.a*T.b;
	return ret;
}
sayouso fT(sayouso T,ll k){
	sayouso ret;
	ret.a=T.a;
	ret.b=T.b;
	return ret;
}
//↑ここまで変える

//要素数(2ベキ)でこれを呼ぶ
void lseguse(ll n){
	lsegN=(node*)calloc(2*n,sizeof(node));
	lsegNUM=n;
	lseg=lsegN+lsegNUM;
	lsegk=0;while(n/=2)lsegk++;
	rep(i,1,2*lsegNUM){
		lsegN[i].x=aid;
		lsegN[i].T=sid;
	}
}
//lseg[i].xに値を与えてから初期化
void lseginit(){
	for(ll i=lsegNUM-1;i>0;i--)lsegN[i].x=xx(lsegN[2*i].x,lsegN[2*i+1].x);
}
void lsegupdatesub(ll l,ll r,sayouso T,ll i,ll cl,ll cr,ll ck){
	if(l>=r)return;
	//disjointなとき
	if(cr<=l||r<=cl)return;
	//完全に含むとき
	if(l<=cl&&cr<=r){
		lsegN[i].T=TT(T,lsegN[i].T);
		return;
	}
	//どちらでもないとき
	//遅延伝播
	lsegN[2*i  ].T=TT(lsegN[i].T,lsegN[2*i  ].T);
	lsegN[2*i+1].T=TT(lsegN[i].T,lsegN[2*i+1].T);
	//再帰的に更新
	ll cm=(cl+cr)/2;
	lsegupdatesub(l,r,T,2*i  ,cl,cm,ck-1);
	lsegupdatesub(l,r,T,2*i+1,cm,cr,ck-1);
	//自身のnodeを更新
	lsegN[i].x=xx(Tx(fT(lsegN[2*i].T,ck-1),lsegN[2*i].x),Tx(fT(lsegN[2*i+1].T,ck-1),lsegN[2*i+1].x));
	lsegN[i].T=sid;
}
void lsegupdate(ll l,ll r,sayouso T){lsegupdatesub(l,r,T,1,0,lsegNUM,lsegk);}
atai lsegcalcsub(ll l,ll r,ll i,ll cl,ll cr,ll ck){
	if(l>=r)return aid;
	//完全に含むとき
	if(l<=cl&&cr<=r)return Tx(fT(lsegN[i].T,ck),lsegN[i].x);

	ll cm=(cl+cr)/2;
	//遅延伝播(変更はないので配るだけで良い)
	lsegN[2*i  ].T=TT(lsegN[i].T,lsegN[2*i  ].T);
	lsegN[2*i+1].T=TT(lsegN[i].T,lsegN[2*i+1].T);
	lsegN[i].x=Tx(fT(lsegN[i].T,ck),lsegN[i].x);
	lsegN[i].T=sid;

	//左側だけ
	if(r<=cm)return lsegcalcsub(l,r,2*i  ,cl,cm,ck-1);
	//右側だけ
	if(cm<=l)return lsegcalcsub(l,r,2*i+1,cm,cr,ck-1);
	//両方
	return xx(lsegcalcsub(l,r,2*i,cl,cm,ck-1),lsegcalcsub(l,r,2*i+1,cm,cr,ck-1));
}
atai lsegcalc(ll l,ll r){return lsegcalcsub(l,r,1,0,lsegNUM,lsegk);}
//遅延セグ木ここまで
//*/


int main(){
	int n,q;
	scanf("%d%d",&n,&q);
	lseguse(1<<17);
	while(q--){
		int t;
		scanf("%d",&t);
		if(t){
			int x,y;
			scanf("%d%d",&x,&y);
			printf("%lld\n",lsegcalc(x,y+1).a);
		}
		else{
			int x,y,b;
			scanf("%d%d%d",&x,&y,&b);
			sayouso T={0,b};
			lsegupdate(x,y+1,T);
		}
	}
}