Three sorting algorithms, in C

s.c

#include <stdio.h>
#include <string.h>

void swap(char* a, char* b) {
  char t = *a;
  *a = *b;
  *b = t;
}

void bubblesort(char* s, int n) {
  int i, j;
  for (i = 0; i < n; i++) {
    for (j = 0; j < n-1; j++) {
      if (s[j] > s[j+1]) {
        swap(&s[j], &s[j+1]);
      }
    }
  }
}

void selectionsort(char* b, int n) {
  if (n < 1) return;

  int j;
  for (j = 0; j < n - 1; j++) {
    int si = j;
    int i;
    for (i = j; i < n; i++) {
      if (b[i] < b[si]) {
        si = i;
      }
    }
    swap(&b[j], &b[si]);
  }
}

void qsort(char* b, int n) {
  if (n <= 1) return;

  int pivot = n / 2; // deal with it.
  swap(&b[pivot], &b[n-1]);

  int s = 0;
  int i;
  for (i = 0; i < n - 1; i++) {
    if (b[i] < b[n - 1]) {
      swap(&b[s], &b[i]);
      s++;
    }
  }
  swap(&b[n-1], &b[s]);
  qsort(b, s);
  qsort(b+s+1, (n-s)-1);
}

int main(int argc, char** argv) {
  int i;
  for (i = 1; i < argc; i++) {
    qsort(argv[i], strlen(argv[i]));
    printf("%s\n", argv[i]);
  }
}