求集合的笛卡尔乘积

#include <stdio.h>
int main()
{
  char A[] = {'1','2'};
  int M = sizeof(A)/sizeof(A[0]);
  char B[] = { 'a','b','c' };
  int N = sizeof(B) / sizeof(B[0]);
  char C[2][2] = { 0 };
  //求C的笛卡尔积，C=A*A
  printf("C=A*A=");
  printf("{");
  int i = 0;
  int j = 0;
  for (i = 0; i < M; i++)
  {
    for (j = 0; j < M; j++)
    {
      C[i][0] = A[i];
      C[i][1] = A[j];
      printf("(%c,%c)", C[i][0], C[i][1]);
    }
  }
  printf("}");
  printf("\n");
  //求D的笛卡尔积，D=A*B
  char D[2][3] = { 0 };
  printf("D=A*B=");
  printf("{");
  for (i = 0; i < M; i++)
  {
    for (j = 0; j < N; j++)
    {
      D[i][0] = A[i];
      D[i][1] = B[j];
      printf("(%c,%c)", D[i][0], D[i][1]);
    }
  }
  printf("}");
  printf("\n");
  //求E的笛卡尔积，E=B*A
  char E[3][2] = { 0 };
  printf("E=B*A=");
  printf("{");
  for (i = 0; i < N; i++)
  {
    for (j = 0; j < M; j++)
    {
      E[i][0] = B[i];
      E[i][1] = A[j];
      printf("(%c,%c)", E[i][0], E[i][1]);
    }
  }
  printf("}");
  printf("\n");
    //求F的笛卡尔积,E=A*A*B
  char F[2][2][3] = { 0 };
  printf("E=A*A*B=");
  printf("{");
  for (i = 0; i < M; i++)
  {
    for (j = 0; j < M; j++)
    {
      for (int k = 0; k < N; k++)
      {
        F[i][j][0] = A[i];
        F[i][j][1] = A[j];
        F[i][j][2] = B[k];
        printf("((%c,%c),%c)", F[i][j][0], F[i][j][1], F[i][j][2]);
      }
    }
    printf("}");
    printf("\n");
  }
      //求G的笛卡尔积，G=A*(A*B)
  char G[2][2][3] = { 0 };      
    printf("G=A*(A*B)=");
    printf("{");
    for (i = 0; i < M; i++)
    {
      for (j = 0; j < M; j++)
      {
        for (int k = 0; k < N; k++)
        {
          G[i][j][0] = A[i];
          G[i][j][1] = A[j];
          G[i][j][2] = B[k];
          printf("(%c,(%c,%c))", G[i][j][0], G[i][j][1], G[i][j][2]);
        }
      }
    }
  printf("}");
  return 0;
}