islem v1.0 - C++

Anonymous

A simple program to find target number with using 6 (or any) numbers and (+,-,/,*) operators

Example:

Target = 673
Numbers = 3, 4, 6, 7, 9, 25

Solution:
25 - 9 = 16
7 * 6 = 42
4 - 3 = 1
42 * 16 = 672
672 + 1 = 673

/*
 * Author: Mete Kart
 *
 * Program: To find target number with using 6 (or any) numbers and (+,-,/,*) operators
 *          (program is unoptimized)
 *
 * Example: Target = 673, Numbers = 3, 4, 6, 7, 9, 25
 * Solution: 25 - 9 = 16; 7 * 6 = 42; 4 - 3 = 1; 42 * 16 = 672; 672 + 1 = 673
 *
 */

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

#define NUMBER_OF_NUMBERS 6

int sol;

typedef struct combi_s {
  int len;
  int num[NUMBER_OF_NUMBERS];
  char buf[128];
} combi_t;

int op (combi_t *r, combi_t *c, int i, int j, int o)
{
  int ret = 0;
  char t[50];
  int m1, m2;

  if (c->num[i] > c->num[j]) {
    m1 = c->num[i];
    m2 = c->num[j];
  } else {
    m1 = c->num[j];
    m2 = c->num[i];
  }

  switch (o) {
    case 0:
      strcpy (r->buf, c->buf);
      r->num[0] = m1 + m2;
      sprintf (t, "%d + %d = %d\n", m1, m2, r->num[0]);
      strcat (r->buf, t);

      ret = 1;
      break;
    case 1:
      strcpy (r->buf, c->buf);
      r->num[0] =  m1 - m2;
      sprintf (t, "%d - %d = %d\n",  m1, m2, r->num[0]);
      strcat (r->buf, t);

      ret = 1;
      break;
    case 2:
      strcpy (r->buf, c->buf);
      r->num[0] =  m1 * m2;
      sprintf (t, "%d * %d = %d\n",  m1, m2, r->num[0]);
      strcat (r->buf, t);

      ret = 1;
      break;
    case 3:
      if (c->num[i] % c->num[j] == 0) {
        strcpy (r->buf, c->buf);
        r->num[0] =  m1 / m2;
        sprintf (t, "%d / %d = %d\n",  m1, m2, r->num[0]);
        strcat (r->buf, t);

        ret = 1;
      } else
        ret = 0;
      break;
    default:
      ret = 0;
      break;
  }

  return ret;
}

void combi (combi_t *c, int target)
{
  int i, j, k, o;

  if (c->len <= 1) {
    if (c->num[0] == target) {
      sol++;
      printf("***** Solution %02d *****\n", sol);
      printf("%s", c->buf);
      printf("***********************\n");
    }
  } else {
    for (i = 0; i < c->len - 1; i++) {
      for (j = i + 1; j < c->len; j++) {

        if (c->num[i] == 0 || c->num[j] == 0 )
          continue;

        for (o = 0; o < 4; o++) {
          int z = 1;
          combi_t r;
          r.len = c->len - 1;

          if (op (&r, c, i, j, o) == 0)
            continue;

          for (k = 0; k < c->len; k++) {
            if (k != i && k != j)
              r.num[z++] = c->num[k];
          }

          combi (&r, target);
        }
      }
    }
  }
}

int main (int argc, char *argv[])
{
  int i, target;

  while (1) {
    combi_t com;
    sol = 0;
    printf("Target: ");
    scanf ("%d", &target);

    for (i = 0; i < NUMBER_OF_NUMBERS; i++) {
      printf("Number %d: ", i + 1);
      scanf ("%d", &com.num[i]);
    }

    com.buf[0] = '\0';
    com.len = NUMBER_OF_NUMBERS;

    combi(&com, target);

    printf("TOTAL %d solution found!\n", sol);
  }

  return 0;
}