selectionsort-c

#include<stdio.h>
#include<stdlib.h>
#include<time.h>

void selection_sort(int a[], int n)
{
    int min_index, temp;

    for(int i = 0; i < n-1; i++)
    {
        min_index = i;

        for(int j = i+1; j < n; j++)
        {
            if(a[j] < a[min_index])
            {
                min_index = j;
            }
        }

        if(min_index != i)
        {
            temp = a[i];
            a[i] = a[min_index];
            a[min_index] = temp;
        }
    }
}


void gen_ran_num(int a[], int n)
{
    for(int i = 0; i < n; i++)
    {
        a[i] = rand() % 10000;
    }
}

int main()
{
    int a[10000];

    clock_t start, end;
    double time_taken;
    double theoretical_time;

    FILE *fp;

    srand(time(NULL));

    fp = fopen("s_time.txt", "w");

    for(int i = 100; i <= 10000; i += 400)
    {
        gen_ran_num(a, i);

        start = clock();
        selection_sort(a, i);
        end = clock();

        time_taken = (double)(end - start) / CLOCKS_PER_SEC;

        theoretical_time = (double)(i * i) * 1e-8;

        fprintf(fp, "%d %lf %lf\n", i, time_taken, theoretical_time);
    }

    fclose(fp);

    FILE *gP = popen("gnuplot -persistent", "w");

    fprintf(gP, "set title 'Selection Sort Time Efficiency'\n");
    fprintf(gP, "set xlabel 'Input Size'\n");
    fprintf(gP, "set ylabel 'Time (seconds)'\n");
    fprintf(gP, "set grid\n");

    fprintf(gP, "set term png\n");
    fprintf(gP, "set output 's_sort_efficiency_c.png'\n");

    fprintf(gP, "plot 's_time.txt' using 1:2 with linespoints title 'Actual Time', \
's_time.txt' using 1:3 with lines lw 2 title 'Theoretical Time'\n");

    pclose(gP);

    return 0;
}