Question

I am getting RUN FAILED (exit value 1, total time: 493ms). I get it when I try to check if a vector has an element from an array in it:

if (find(cycles.begin(), cycles.end(), permutation[i]) == cycles.end()) {
     startCycle = permutation[i];
     break;
}

The full code of the program:

#include <stdio.h>
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

#define TESTING_FILE_IN
//#define TESTING_FILE_OUT
#define DEBUG
//#define SHOW_TIMING

vector< int > cycles;
int permutation[1001];

/*
 * 
 */
int main() {

    #ifdef TESTING_FILE_IN
    freopen("in.txt", "r", stdin);
    #endif

    int ind, startCycle, n, count, elemProc;

    scanf("%d", &n); //Number of elements in the permutation

    for (int i = 0; i < n; i++) {
        cin >> permutation[i];
    }   

    // Calculate cycles
    startCycle = 1;
    while (true) {
        cycles.push_back(ind + 1);
        elemProc++;
        ind = permutation[ind] - 1;
        if (ind == startCycle) {
            cycles.push_back(startCycle);
            cycles.push_back(-1);
            count++;
            for (int i = 0; i < n; i++) {
                if (find(cycles.begin(), cycles.end(), permutation[i]) == cycles.end()) {
                    startCycle = permutation[i];
                    break;
                }
            }
        }
        if (elemProc == n)
            break;
    }

    cout << count << endl;
    for (int i = 0; i < cycles.size(); ++i) {
        if (cycles[i] != -1)
            cout << cycles[i] << " ";
        else
            cout << endl;
    }

    return 0;
}

When I comment a piece of code that does the searching, it builds and runs okay. Hope you’ll be able to help me. Thanks in advance.

Answer 1

You might think that local variables automatically have initial value of zero when you define them. That’s not the case. For a non-static local variable of build-in type without an initializer, its initial value can be anything.

       v----you should initialize these local variables
   int ind, startCycle, n, count, elemProc;

You may define them as

   int ind = 0, startCycle = 0, n = 0, count = 0, elemProc = 0;