Submission #1019677

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019677		Minbaev	K-th path (IZhO11_kthpath)	C++17	0 / 100	1 ms	348 KiB

kthpath

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
 
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
 
using namespace std;
using namespace __gnu_pbds;
 
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define f first
#define s second
#define int long long
#define pii pair<int,int>
 
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
 
template<class T>
using Tree = tree<T, null_type, less<T>, rb_tree_tag,
    tree_order_statistics_node_update>;
 
const int inf = 1e17 + 7;
const int mod = 1e9 + 7;
const int N = 3e5 + 5;

int binpow(int a, int b){
	if(b == 0)return 1;
	if(b % 2 == 0){
		int c = binpow(a,b/2);
		return (c*c)%mod;
	}
	return (binpow(a,b-1)*a)%mod;
}

int divi(int a, int b){
	return (a*(binpow(b,mod-2)))%mod;
}

int n,m,k;
int cnk(int a, int b){
	int a1 = 1;
	for(int i = a-b+1;i<=a;i++)a1 *= i;
	int b1 = 1;
	for(int i = 1;i<=b;i++)b1 *= i;
	return (int)a1/b1;
}

void solve(){
	
	cin >> n >> m;
	char arr[35][35];
	
	for(int i = 1;i<=n;i++){
		for(int j = 1;j<=m;j++){
			cin >> arr[i][j];
		}
	}
	
	cin >> k;
	
	int sum = 0;
	vector<char>ans;
	ans.pb(arr[1][1]);
	
	int i = 1,j = 1;
	while(i < n && j < m){
		if(arr[i+1][j] <= arr[i][j+1]){
			if(sum + cnk(m+n-i-j-1, n-i-1) >= k){
				ans .pb( arr[i+1][j]);
				i += 1;
			}
			else{
				ans .pb( arr[i][j+1]);
				j += 1;
				sum += cnk(m+n-i-j-1, n-i-1);
			}
		}
		else{
			if(sum + cnk(m+n-i-j-1, m-j-1) >= k){
				ans .pb( arr[i][j+1]);
				j += 1;
			}
			else{
				ans .pb( arr[i+1][j]);
				j += 1;
				sum += cnk(m+n-i-j-1, m-j-1);
			}
		}
	}
	
	while(i < n){
		i += 1;
		ans .pb( arr[i][j]);
	}
	
	while(j < m){
		j += 1;
		ans .pb( arr[i][j]);
	}
	
	for(auto to:ans)cout << to;
	
	
}
 
 signed main()
{
//	freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);

	ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
	int tt=1;//cin>>tt;
	while(tt--)solve();
 
}
 

• Subtask 1: 0 / 100