Submission #742563

#	Time	Username	Problem	Language	Result	Execution time	Memory
742563		Dan4Life	Fancy Fence (CEOI20_fancyfence)	C++17	0 / 100	2 ms	340 KiB

fancyfence

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pb push_back
#define sz(a) (int)a.size()
const int mxN = (int)1e5+10;
const int MOD = (int)1e9+7;

int Tw, Th, inv;
int n, h[mxN], w[mxN];
vector<pair<int,int>> v;

int poww(int a, int b){
	if(!b) return 1;
	int x = poww(a,b/2);
	x*=x, x%=MOD;
	if(b&1) x*=a, x%=MOD;
	return x;
}

int mul(int a, int b) { return a*b % MOD; }
int comb(int a){return mul(mul(a,a+1),inv);}

int32_t main(){
	cin >> n; int ans = 0; inv = poww(2,MOD-2);
	for(int i = 1; i <= n; i++) cin >> h[i];
	for(int i = 1; i <= n; i++) cin >> w[i];
	for(int i = 1; i <= n; i++){
		int W = w[i]; Tw+=w[i], Th+=h[i]; Tw%=MOD, Th%=MOD;
		while(i<n and h[i]==h[i+1]) W+=w[++i], W%=MOD;
		v.pb({h[i],W});
	}
	cout << mul(comb(Tw),comb(Th)); return 0;
	n = sz(v);
	for(auto [h,w] : v){
 		if(h==1) continue;
		ans+=comb(w)*2, ans%=MOD;
	}
	cout << ans;
}

• Subtask 1: 0 / 0
• Subtask 2: 0 / 12
• Subtask 3: 0 / 13
• Subtask 4: 0 / 15
• Subtask 5: 0 / 15
• Subtask 6: 0 / 18
• Subtask 7: 0 / 27