集合的运算

#include <stdio.h>
#include <stdlib.h>
void print(int size, char arr[])
{
  if (size == 0) {
    printf("null");
  }
  for (int i = 0; i < size; i++) {
    printf("%c", arr[i]);
  }
  printf("\n");
}
int main()
{
  char U[] = { 'a','b','c','d','e','f','g','h' };
  char A[] = { 'a','b','c','g' };
  char B[] = { 'd','e','f','g' };
  char C[] = { 'a','c','f' };
  char D[] = { 'f','h' };
  int M = sizeof(A) / sizeof(A[0]);//计算A集合的大小
  int N = sizeof(B) / sizeof(B[0]);//计算B集合的大小
  int P = sizeof(C) / sizeof(C[0]);//计算C集合的大小
  int Q = sizeof(D) / sizeof(D[0]);//计算D集合的大小
  int R = sizeof(U) / sizeof(U[0]);//计算U集合的大小
  char E[100] = { '0' };
  char F[100] = { '0' };
  char G[100] = { '0' };
  char H[100] = { '0' };
  char I[100] = { '0' };
  char J[100] = { '0' };
  char K[100] = { '0' };
  char L[100] = { '0' };
  int size = 0;//标记结果集合的大小
  for (int i = 0; i < M; i++) {
    for (int j = 0; j < N; j++) {
      if (A[i] == B[j]) {
        E[size] = A[i];
        size++;
        break;
      }
    }
  }
  printf("A∩B    ：");
  print(size, E);
  int Size = 0;
  for (int i = 0; i < size; i++) {
    int find = 0;
    for (int j = 0; j < P; j++) {
      if (E[i] == C[j]) {
        find = 1;
        break;
      }
    }
    if (find == 0) {
      K[Size] = E[i];
      Size++;
    }
  }
  printf("(A∩B)-C:");
  print(Size, K);
  size = 0;
  for (int i = 0; i < N; i++) {
    for (int j = 0; j < P; j++) {
      for (int k = 0; k < Q; k++) {
        if ((B[i] == C[j]) && (C[j] == D[k]))
        {
          G[size] = B[i];
          size++;
        }
      }
    }
  }
  printf("B∩C∩D  ：");
  print(size, G);
  size = 0;
  for (int i = 0; i < N; i++) {
    F[size] = B[i];
    size++;
  }
  for (int i = 0; i < P; i++) {
    int find = 0;
    for (int j = 0; j < N; j++) {
      if (C[i] == B[j]) {
        find = 1;
        break;
      }
    }
    if (find == 0) {
      F[size] = C[i];
      size++;
    }
  }
  printf("B∪C    ：");
  print(size, F);
  Size = 0;
  for (int i = 0; i < M; i++) {
    for (int j = 0; j < size; j++) {
      if (A[i] == F[j]) {
        J[Size] = A[i];
        Size++;
      }
    }
  }
  printf("A∩(B∪C)：");
  print(Size, J);
  Size = 0;
  for (int i = 0; i < size; i++) {
    L[Size] = F[i];
    Size++;
  }
  for (int i = 0; i < M; i++) {
    int find = 0;
    for (int j = 0; j < size; j++) {
      if (A[i] == F[j]) {
        find = 1;
        break;
      }
    }
    if (find == 0) {
      L[Size] = A[i];
      Size++;
    }
  }
  printf("A∪B∪C  :");
  print(Size, L);
  size = 0;
  for (int i = 0; i < R; i++) {
    int find = 1;
    for (int j = 0; j < M; j++) {
      if (U[i] == A[j]) {
        find = 0;
        break;
      }
    }
    if (find == 1) {
      H[size] = U[i];
      size++;
    }
  }
  printf("A的补集：");
  print(size, H);
  size = 0;
  for (int i = 0; i < P; i++) {
    int find = 0;
    for (int j = 0; j < Q; j++) {
      if (C[i] == D[j]) {
        find = 1;
        break;
      }
    }
    if (find == 0) {
      I[size] = C[i];
      size++;
    }
  }
  printf("C-D    ：");
  print(size, I);
  Size = 0;
  return 0;
}