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input/code.cpp: In function 'bool isSafe(int, std::vector<std::vector<bool> >, int*, int)':
input/code.cpp:9:9: warning: unused variable 'V' [-Wunused-variable]
    9 |     int V = graph.size();
      |         ^

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


bool isSafe(int v, vector<vector<bool>> graph, 
            int path[], int pos) 
{ 
    int V = graph.size();

    if (graph [path[pos - 1]][ v ] == 0) 
        return false; 

  
    for (int i = 0; i < pos; i++) 
        if (path[i] == v) 
            return false; 

    return true; 
} 

bool hamCycleUtil(vector<vector<bool>> graph, 
                  int path[], int pos) 
{ 
    int V = graph.size();
    if (pos == V) 
    { 
        if (graph[path[pos - 1]][path[0]] == 1) 
            return true; 
        else
            return false; 
    } 
    for (int v = 1; v < V; v++) 
    { 
        if (isSafe(v, graph, path, pos)) 
        { 
            path[pos] = v; 

            if (hamCycleUtil (graph, path, pos + 1) == true) 
                return true; 

            path[pos] = -1; 
        } 
    } 

    return false; 
} 

void printSolution(int path[], int V, int n, int m) 
{  
    int from_x=0;
    int from_y=0;

    for (int i = 1; i < V; i++){
        int y = path[i] / m; 
        int x = path[i] % m;

        if(y>from_y)cout<<"D";
        else if(y<from_y)cout<<"U";
        else if(x>from_x)cout<<"R";
        else if(x<from_x)cout<<"L";

        from_x = x;
        from_y = y;

    } 

    //cout << "  /" << from_x << " , " << from_y << "/  ";

    if(from_y<0)cout<<"D";
    else if(from_y>0)cout<<"U";
    else if(from_x<0)cout<<"R";
    else if(from_x>0)cout<<"L";


    cout << endl;
} 


bool hamCycle(vector<vector<bool>> graph, int n, int m) 
{ 
    int V = graph.size();
    int *path = new int[V]; 
    for (int i = 0; i < V; i++) 
        path[i] = -1; 

    path[0] = 0; 
    if (hamCycleUtil(graph, path, 1) == false ) 
    { 
        cout << -1 << endl; 
        return false; 
    } 

    printSolution(path, V, n, m); 
    return true; 
} 


int main() 
{ 

    int m,n;

    cin >> n >> m;
    vector<vector<bool>> adj(n*m, vector<bool>(n*m,0));

    
    
    for(int i=0; i<n; i++){
        for(int l=0; l<m; l++){
            if(i-1>=0){
                adj[i*m + l][(i-1)*m +l] = 1;
            }
            if(i+1<n){
                adj[i*m + l][(i+1)*m +l] = 1;
            }
            if(l-1>=0){
                adj[i*m + l][i*m +l-1] = 1;
            }
            if(l+1<m){
                adj[i*m + l][i*m +l+1] = 1;
            }

        }
    }

    hamCycle(adj, n, m); 
    
    return 0; 
} 

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

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Test 12

Verdict: ACCEPTED

Test 13

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Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED

Test 17

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Test 18

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Test 19

Verdict: ACCEPTED

Test 20

Verdict: ACCEPTED

Test 21

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Test 22

Verdict: ACCEPTED

Test 23

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Test 24

Verdict: ACCEPTED

Test 25

Verdict: ACCEPTED

Test 26

Verdict: ACCEPTED

Test 27

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Test 28

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Test 29

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Test 30

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Test 47

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Test 48

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Test 49

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Test 51

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Test 53

Verdict: RUNTIME ERROR

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Test 56

Verdict: TIME LIMIT EXCEEDED