Submission #338201

#	Time	Username	Problem	Language	Result	Execution time	Memory
338201		tengiz05	K-th path (IZhO11_kthpath)	C++17	100 / 100	2 ms	384 KiB

kthpath

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define FASTIO ios_base::sync_with_stdio(false); cin.tie(NULL);
#define all(x) (x).begin(), (x).end()
#define pb push_back
#define pii pair<int, int>
#define ff first
#define ss second
#define PI acos(-1)
#define ld long double
template<class T> bool ckmin(T& a, const T& b) {return a>b? a=b, true:false;}
template<class T> bool ckmax(T& a, const T& b) {return a<b? a=b, true:false;}
const int mod = 1e9+7, N = 35;
int msb(int val){return sizeof(int)*8-__builtin_clzll(val)-1;}
int n, m, k;
char a[N][N];
char ans[N+N];
int dp[N][N];
int rec(int x, int y){
	if(~dp[x][y])return dp[x][y];
	if(ans[x+y+1] == '{'){
		dp[x][y] = 0;
		if(x+1 < n)dp[x][y] += rec(x+1,y);
		if(y+1 < m)dp[x][y] += rec(x,y+1);
		return dp[x][y];
	}
	dp[x][y] = 0;
	if(x+1 < n && ans[x+y+1] == a[x+1][y]){
		dp[x][y] += rec(x+1,y);
	}if(y+1 < m && ans[x+y+1] == a[x][y+1]){
		dp[x][y] += rec(x,y+1);
	}return dp[x][y];
}
void solve(int test_case){
	int i, j;
	cin >> n >> m;
	for(i=0;i<n;i++){
		for(j=0;j<m;j++){
			cin >> a[i][j];
		}
	}
	cin >> k;
	ans[0] = a[0][0];
	for(i=1;i<n+m;i++)ans[i] = '{';
	memset(dp, -1, sizeof(dp));
	dp[n-1][m-1] = 1;
	for(i=1;i<n+m-1;i++){
		char c;
		for(c = 'a'; c <= 'z'; c++){
			ans[i] = c;
			memset(dp, -1, sizeof(dp));
			dp[n-1][m-1] = 1;
			int tmp = rec(0,0);
			if(tmp >= k){
				break;
			}k -= tmp;
		}
		
	}
	for(i=0;i<n+m-1;i++)cout << ans[i];
	cout << '\n';
	return;
}

signed main(){
	FASTIO;
#define MULTITEST 0
#if MULTITEST
	int _T;
	cin >> _T;
	for(int T_CASE = 1; T_CASE <= _T; T_CASE++)
		solve(T_CASE);
#else
	solve(1);
#endif
	return 0;
}

• Subtask 1: 100 / 100