A solution for Project Two

/* MCS 275 Project Two: Scrabble */

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

int *match_positions (char s1[], char s2[]);
/* maches the positions in s1 with s2 as follows,
   for pos = match_positions(s1,s2) :
   if s1[i] == s2[j], then pos[i] = j (first occurrence)
   otherwise if s1[i] does not occur in s2[j], pos[i] = -1;
   returns the number of positions that match. */
void cross_words (char s1[], char s2[], int pos[]);
/* writes the words s1 and s2 so that they cross */

int main(int argc, char *argv[])
{
   int *pos;
   if (argc > 2)
   {
      pos = match_positions(argv[1],argv[2]);
      cross_words(argv[1],argv[2],pos);
   }
   else
   {
      printf("We need two words to scrabble.\n");
      printf("Please call again.\n");
   }
}

int *match_positions (char s1[], char s2[])
{
   int i,j;
   int len=strlen(s1);
   int *pos;
   pos = (int*)calloc(len,sizeof(int));
   for (i=0; i < len; i++)        /* scan string s1 */
   {
      pos[i]=-1;
      for (j=0; s2[j] != '\0' ; j++)     /* search for match in s2 */
         if (s1[i]==s2[j])
         {
            pos[i]=j; break;    /* need first match, so break out */
         }
   }
   return pos;
}

void cross_words (char s1[], char s2[], int pos[])
{
   int lens1 = strlen(s1);
   int lens2 = strlen(s2);
   int i,j,row;
   int minrow = 2*lens2-2;               /* minimal row in display */
   int maxrow = 0;                       /* maximal row in display */
   char display[2*lens2-1][lens1];
   for (i=0; i < 2*lens2-1; i++)         /* initialize display */
      for (j=0; j= 0; i--)
            display[row--][j] = s2[i];
         if (row+1 < minrow) minrow = row+1;
         row = lens2;
         for (i=pos[j]+1; s2[i] != '\0'; i++)
            display[row++][j] = s2[i];
         if (row-1 > maxrow) maxrow = row-1;
      }
   if (minrow <= maxrow)
   {
      printf("Crossing \"%s\" with \"%s\" :\n",s1,s2);
      for (i=minrow; i < maxrow+1; i++)   /* print the display */
      {
         for (j=0; j < lens1; j++)
            putchar(display[i][j]);
         printf("\n");
      }
   }
   else
      printf("\"%s\" does not cross with \"%s\".\n",s1,s2);
}