Data Structure lab

#include <stdio.h>
#include <stdlib.h>
#define MAX 20

int graph[MAX][MAX], visited[MAX], n;

// Create the graph
void createGraph() {
    printf("Enter number of cities: ");
    scanf("%d", &n);
    printf("Enter the adjacency matrix:\n");
    for (int i = 0; i < n; i++)
        for (int j = 0; j < n; j++)
            scanf("%d", &graph[i][j]);
}

// DFS Traversal
void DFS(int v) {
    visited[v] = 1;
    printf("City %d ", v);
    for (int i = 0; i < n; i++) {
        if (graph[v][i] == 1 && !visited[i])
            DFS(i);
    }
}

// BFS Traversal
void BFS(int start) {
    int queue[MAX], front = 0, rear = 0;
    for (int i = 0; i < n; i++) visited[i] = 0;

    visited[start] = 1;
    queue[rear++] = start;

    while (front < rear) {
        int v = queue[front++];
        printf("City %d ", v);
        for (int i = 0; i < n; i++) {
            if (graph[v][i] == 1 && !visited[i]) {
                queue[rear++] = i;
                visited[i] = 1;
            }
        }
    }
}

int main() {
    int choice, start;
    while (1) {
        printf("\n--- MENU ---\n");
        printf("1. Create Graph\n");
        printf("2. DFS Traversal\n");
        printf("3. BFS Traversal\n");
        printf("4. Exit\n");
        printf("Enter your choice: ");
        scanf("%d", &choice);
        switch (choice) {
            case 1:
                createGraph();
                break;
            case 2:
                printf("Enter starting city (0 to %d): ", n - 1);
                scanf("%d", &start);
                for (int i = 0; i < n; i++) visited[i] = 0;
                printf("DFS Traversal from City %d: ", start);
                DFS(start);
                printf("\n");
                break;
            case 3:
                printf("Enter starting city (0 to %d): ", n - 1);
                scanf("%d", &start);
                printf("BFS Traversal from City %d: ", start);
                BFS(start);
                printf("\n");
                break;
            case 4:
                exit(0);
            default:
                printf("Invalid choice!\n");
        }
    }
}

               


  

Menu:
1. Create Graph
2. DFS
3. BFS
4. Exit
Enter choice: 1
Enter number of cities: 4
Enter adjacency matrix (0/1):
0 1 1 0
0 0 1 1
0 0 0 1
0 0 0 0

Menu:
1. Create Graph
2. DFS
3. BFS
4. Exit
Enter choice: 2
Enter starting city (0 to 3): 2
DFS Traversal: City 2 City 3 

Menu:
1. Create Graph
2. DFS
3. BFS
4. Exit
Enter choice: 3
Enter starting city (0 to 3): 4
BFS Traversal: City 4 

Menu:
1. Create Graph
2. DFS
3. BFS
4. Exit
Enter choice: 4