DFS in C: solved exercise

DFS in C: solved exercise

This exercise is scheduled for daily publication and follows the standard site structure: statement, solution, and expected output.

Problem statement

Solve the practical case and verify the console output.

C solution

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#include <stdio.h>

void dfs(int nodo, int vis[]) {
    vis[nodo] = 1;
    printf("%d ", nodo);
    if (nodo == 0 && !vis[1]) dfs(1, vis);
    if (nodo == 1 && !vis[2]) dfs(2, vis);
    if (nodo == 2 && !vis[3]) dfs(3, vis);
}

int main(void) {
    int vis[4] = {0};
    printf("DFS: ");
    dfs(0, vis);
    printf("\n");
    return 0;
}

Expected output

1

DFS: 0 1 2 3

Common mistakes

  • Not validating standard-function return values.
  • Ignoring edge cases for indices, pointers, or buffers.
  • Skipping example-based test runs before publishing.

Practical use

DFS is used in cycle detection, topological sorting, maze solving, and connected component analysis.

Guided practice and full book

If you want a complete path with progressive difficulty:

FAQ

Is this exercise useful for C exams and technical interviews?

Yes. It targets patterns that commonly appear in practice assignments, technical interviews, and C programming exams.

Where can I keep practicing with more solved C exercises?

In Programming in C in 100 Solved Exercises and C Exercises. Kindle Unlimited: View on Amazon.

How should I practice this exercise type to improve faster?

Start with small inputs, run edge cases (empty, one item, max capacity), then rewrite the solution from scratch without copying.