E3-I

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
#include <time.h>
#pragma warning(disable:4996 6031)
int main(){
    int op, group = 0, i, count;
    char tmp[32] = { 0 };
    while(~scanf("%d", &op)){
        if(op == 0){
            group++;
            printf("Case %d:\n", group);
            count = 0;
            unsigned int s;
            scanf("%u", &s);
            char tmp[32] = { 0 };
            for(i = 0; i < 26; i++){
                if(s & (1u << i)){
                    tmp[count] = 'a' + i;
                    count++;
                }
            }
            if(count){
                putchar('{');
                for(i = 0; i < count - 1; i++){
                    putchar(tmp[i]);
                    putchar(',');
                }
                putchar(tmp[count - 1]);
                putchar('}');
                putchar('\n');
            }
            else{
                puts("Empty set");
            }
        }
        else if(op == 1){
            group++;
            printf("Case %d:\n", group);
            int a, b, x;
            char A[32] = { 0 }, B[32] = { 0 };
            //hint
            scanf("%d%d%d", &a, &b, &x);
            while((A[0] = getchar()) < 'a' || A[0] > 'z');
            for(i = 1; i < a; i++)
                A[i] = getchar();
            while((B[0] = getchar()) < 'a' || B[0] > 'z');
            for(i = 1; i < b; i++)
                B[i] = getchar();
            //hint
            //puts(A);
            //puts(B);
            unsigned int a0 = 0, b0 = 0;
            for(i = 0; i < a; i++){
                a0 |= (1u << (A[i] - 'a'));
            }
            for(i = 0; i < b; i++){
                b0 |= (1u << (B[i] - 'a'));
            }
            if(a0 == b0){
                puts("Set A is equal to set B!");
            }
            else{
                if((a0 & b0) == a0){
                    puts("Set A is the subset of set B!");
                }
                else if((a0 & b0) == b0){
                    puts("Set B is the subset of set A!");
                }
                else{
                    puts("No subset relationship!");
                }
                unsigned int result = 0;
                switch(x){
                    case 1:
                        result = a0 | b0;
                        printf("The union of set A and set B is:");
                        break;
                    case 2:
                        result = ~a0;
                        printf("The complement of set A is:");
                        break;
                    case 3:
                        result = a0 & (~b0);
                        printf("The difference of set A and set B is:");
                        break;
                    case 4:
                        result = ~(a0 & b0);
                        printf("The complement of the intersection of set A and set B is:");
                        break;
                    case 5:
                        result = ~(a0 | b0);
                        printf("The complement of the union of set A and set B is:");
                        break;
                    default://0
                        result = a0 & b0;
                        printf("The intersection of set A and set B is:");
                        break;
                }
                if(result & ((1u << 26) - 1)){
                    putchar('{');
                    count = 0;
                    for(i = 0; i < 26; i++){
                        if(result & (1u << i)){
                            tmp[count] = 'a' + i;
                            count++;
                        }
                    }
                    for(i = 0; i < count - 1; i++){
                        putchar(tmp[i]);
                        putchar(',');
                    }
                    putchar(tmp[count - 1]);
                    putchar('}');
                    putchar('\n');
                }
                else{
                    puts("Empty set");
                }
            }
        }
    }
    return 0;
}