예제 #1
0
파일: test.c 프로젝트: mridul88/Programs
int no_path(int a[], int n, int start)
{
    static int count =0;
    if(start == n-1)
    {
        count++;
        return count;
    }
    if(start+1<n)
        no_path(a,n,start+1);
    if(start+2<n)
            no_path(a,n,start+2);

    return count;
}
예제 #2
0
파일: short.c 프로젝트: mhspradlin/c
struct path *find_shortest_ (int **weights, struct path **cache, struct node **graph, int id1, int id2) {
    printf ("id1: %d, id2: %d\n", id1, id2);
    if (id1 == id2) {
        struct path *stub = new_path (id1);
        cache[id1] = stub;
        return stub;
    }

    // If the path passed to us is a cycl
    
    //struct node *start = get_node (graph, id1);
    struct node *end = get_node (graph, id2);

    // Get all of the shortest paths for the predecessors
    // Also, the shortest path to us is us plus the shortest of the paths to our
    // predecessors
    int i;
    int min = 65535;
    int minpath = 0;
    for (i = 0; i < end->num_back; i++) {
        struct path *cur = cache[end->back[i]];
        // Only do work if we have to
        if (cur == NULL) {
            cur = find_shortest_ (weights, cache, graph, id1, end->back[i]);
        }
	    // Now we definitely have a value
        if (cur->numelems > 0 && cur->length + weights[end->back[i]][id2] < min) {
            min = cur->length + weights[end->back[i]][id2];
            minpath = end->back[i];
        }
    }

    // If there's no path, return that
    // We also get here if there's nobody behind us
    if (min == 65535)
        return no_path ();


    // Add us to the cache and return
    struct path *our_shortest = add_stop (weights, cache[minpath], minpath, id2);

    // If we've cycled (only happens if there's a negative cycle) then print out
    // that we have a negative cycle and the path that has it
    // Might not terminate if we do... Hmm...
    if (has_cycle (our_shortest)) {
        printf ("======== We have a cycle =======\n");
        print_path (our_shortest);
        printf("================\n");
    }

    // Add us to the cache
    cache[id2] = our_shortest;
    return our_shortest;
}