Cod sursă (job #800844)

#include <bits/stdc++.h>
using namespace std;

ifstream fin("immortal.in");
ofstream fout("immortal.out");

bool found=false;
void back(vector<vector<int>> a, vector<vector<int>> raspuns, int I, int n, int m, int k)
    {
        if(found) return;
        if(I==1)
            {
                found=true;
                //afisare(raspuns):
                for(int i=0; i<raspuns.size()-1; i++)
                {
                    for(int j=0; j<raspuns[1].size(); j++)
                        fout<<raspuns[i][j]<<" ";
                    fout<<"\n";
                }
                return;
            }
        for(int i=1; i<=n; i++)
        {
            for(int j=1; j<=m; j++)
            {
                //sus
                if(i-2>0 && a[i-2][j]==0 && a[i-1][j]==1 && a[i][j]==1)
                    {
                        a[i][j]=0;
                        a[i-1][j]=0;
                        a[i-2][j]=1;
                        raspuns[k][0]=i;
                        raspuns[k][1]=j;
                        raspuns[k][2]=i-2;
                        raspuns[k][3]=j;
                        back(a, raspuns, I-1, n, m, k+1);
                        raspuns[k][0]=0; //de aici
                        raspuns[k][1]=0;
                        raspuns[k][2]=0;
                        raspuns[k][3]=0;
                        a[i][j]=1;
                        a[i-1][j]=1;
                        a[i-2][j]=0;     //pana aici e backtracking-ul
                    }
                //stanga
                if(j-2>0 && a[i][j-2]==0 && a[i][j-1]==1 && a[i][j]==1)
                    {
                        a[i][j]=0;
                        a[i][j-1]=0;
                        a[i][j-2]=1;
                        raspuns[k][0]=i;
                        raspuns[k][1]=j;
                        raspuns[k][2]=i;
                        raspuns[k][3]=j-2;
                        back(a, raspuns, I-1, n, m, k+1);
                        raspuns[k][0]=0; //de aici
                        raspuns[k][1]=0;
                        raspuns[k][2]=0;
                        raspuns[k][3]=0;
                        a[i][j]=1;
                        a[i][j-1]=1;
                        a[i][j-2]=0;     //pana aici e backtracking-ul
                    }
                //dreapta
                if(j+2<=n && a[i][j+2]==0 && a[i][j+1]==1 && a[i][j]==1)
                    {
                        a[i][j]=0;
                        a[i][j+1]=0;
                        a[i][j+2]=1;
                        raspuns[k][0]=i;
                        raspuns[k][1]=j;
                        raspuns[k][2]=i;
                        raspuns[k][3]=j+2;
                        back(a, raspuns, I-1, n, m, k+1);
                        raspuns[k][0]=0; //de aici
                        raspuns[k][1]=0;
                        raspuns[k][2]=0;
                        raspuns[k][3]=0;
                        a[i][j]=1;
                        a[i][j+1]=1;
                        a[i][j+2]=0;     //pana aici e backtracking-ul
                    }
            }
        }
    }

int main() {
    int n,m,I;
    fin>>n>>m>>I;
    vector<vector<int>> a(n+1, vector<int>(m+1, 0)), raspuns(I, vector<int>(4, 0));
    for (int i=1; i<=I; i++) {
        int a1, a2;
        fin>>a1>>a2;
        a[a1][a2]=1;
    }
    back(a, raspuns, I, n, m, 0);
    return 0;
}