Submission #1688880

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Source Code Expand

#include<bits/stdc++.h>
#define range(i,a,b) for(int i = (a); i < (b); i++)
#define rep(i,b) for(int i = 0; i < (b); i++)
#define all(a) (a).begin(), (a).end()
#define show(x)  cerr << #x << " = " << (x) << endl;
//const int INF = 1e8;
using namespace std;
const int M = 1000000007;

int main(){
	int n;
	cin >> n;

	vector<long long> t(n + 2), a(n + 2);
	rep(i,n) cin >> t[i + 1];
	rep(i,n) cin >> a[i + 1];
	t[0] = -1;
	a[n + 1] = -1;

	vector<long long> T(n + 2, 0);
	vector<long long> k(n + 2);
	rep(i,n){
		if(t[i] != t[i + 1]){
			T[i + 1] = true;
		}
		k[i + 1] = t[i + 1];
	}
	T[1] = true;
	//rep(i,n + 2){ cout << k[i] << ' '; }cout << endl;

	for(int i = n + 1; i >= 2; i--){
		if(T[i - 1]) continue;
		if(a[i] != a[i - 1]){
			T[i - 1] = true;
		}
		k[i - 1] = min(k[i - 1], a[i - 1]);
	}
	T[n] = true;
	//rep(i,n + 2){ cout << k[i] << ' '; }cout << endl;
	
	int cur = 0;
	range(i,1,n + 1){
		cur = k[i];
		if(cur > t[i]){
			cout << 0 << endl;
			return 0;
		}
	}
	cur = 0;
	for(int i = n; i >= 1; i--){
		cur = k[i];
		if(cur > a[i]){
			cout << 0 << endl;
			return 0;
		}
	}

	long long ans = 1;
	range(i,1,n + 1){
		if(not T[i]) (ans *= k[i]) %= M;
	}

	cout << ans << endl;
}

Submission Info

Judge Result