Fixed (I think) threesum

threesum_fixed_i_think.c

/*
 * threesum.c
 */

#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <unistd.h>

#ifndef MAX_ELEMENTS
#define MAX_ELEMENTS        10
#endif /* MAX_ELEMENTS */

#ifndef CLOCKS_PER_SEC
#error CLOCKS_PER_SEC not defined on this platform
#endif /* CLOCKS_PER_SEC */


static
long int count(long int *a)
{
    int     counting, i, j, k;


    counting = 0;
    for ( i = 0; i < MAX_ELEMENTS - 2; i++ )
        for ( j = i+1; j < MAX_ELEMENTS - 1; j++ )
            for ( k = j+1; k < MAX_ELEMENTS; k++ )
                if ( (a[i] + a[j] + a[k]) == 0 ) {
                    counting++;
                    printf("Triplet Found : %ld, %ld, %ld\n", a[i], a[j], a[k]);
                };

   return counting;
}


int main(int  argc, char * const  argv[])
{
    long int        arr[MAX_ELEMENTS], i, cnt; 
    clock_t         start_time, end_time;
    double          total_time;
    FILE            *fp;


    switch ( argc ) {
        case 1:
            fp = stdin;
            break;
        case 2:
            if ( (fp = fopen(argv[1], "r")) == NULL ) {
                fprintf(stderr, "Could not open input file: %s\n", strerror(errno));
                return 2;
            };
            break;
        default:
            fprintf(stderr, "Usage: %s [ FILE ]\n", argv[0]);
            return 1;
            break;
    };

    start_time = clock();
    printf("Starting of the program: = %ld\n", start_time);

    for ( i = 0; i < MAX_ELEMENTS; i++ ) { 
        fscanf(fp,"%ld", &arr[i]);
        printf("%ld\n", arr[i]);
    };

    fclose(fp);
    cnt = count(arr);
    end_time = clock();

    printf("Result: %ld\n", cnt);

    total_time = (double)(end_time - start_time) / CLOCKS_PER_SEC;
    printf("Total time taken by CPU: %f\n", total_time);
    return 0;
}

/* vim: set filetype=c expandtab tabstop=4 sts=4 shiftwidth=4: */