Submission #881098

#	Time	Username	Problem	Language	Result	Execution time	Memory
881098		alexdd	K-th path (IZhO11_kthpath)	C++17	100 / 100	2 ms	452 KiB

kthpath

#include<iostream>
using namespace std;
#define int long long
const int INF = 1e18;
int n,m,k;
string s;
char mat[35][35];
int dp[35][35][2];
int calc()
{
    dp[1][1][1] = 1;
    dp[1][1][0] = 0;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            if(i==1 && j==1)
                continue;
            if(mat[i][j]==s[i+j-1])
            {
                dp[i][j][1] = min(INF+5, dp[i-1][j][1] + dp[i][j-1][1]);
                dp[i][j][0] = min(INF+5, dp[i-1][j][0] + dp[i][j-1][0]);
            }
            else if(mat[i][j] < s[i+j-1])
            {
                dp[i][j][1] = 0;
                dp[i][j][0] = min(INF+5, dp[i-1][j][0] + dp[i-1][j][1] + dp[i][j-1][0] + dp[i][j-1][1]);
            }
            else
            {
                dp[i][j][1] = 0;
                dp[i][j][0] = min(INF+5, dp[i-1][j][0] + dp[i][j-1][0]);
            }
        }
    }
    return min(INF+5, dp[n][m][0]);
}
signed main()
{
    cin>>n>>m;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=m;j++)
        {
            cin>>mat[i][j];
        }
    }
    cin>>k;
    s = "#";
    s.push_back(mat[1][1]);
    for(int i=2;i<=n+m-1;i++)
    {
        s.push_back('a'-1);
    }
    for(int i=2;i<=n+m-1;i++)
    {
        for(int j=26-1;j>=0;j--)
        {
            s[i] = j + 'a';
            if(calc() <= k-1)
            {
                break;
            }
        }
    }
    for(int i=1;i<=n+m-1;i++)
        cout<<s[i];
    return 0;
}

• Subtask 1: 100 / 100