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

typedef struct exp Exp;
typedef struct stm Stm;

typedef enum
{
    INT,
    ID,
    ADD,
    TIME
}Exp_kind;

typedef enum
{
    ASSIGN,
    PRINT
}Stm_kind;

typedef struct
{
    Exp* left;
    Exp* right;
}Exp_add;

typedef struct
{
    Exp* left;
    Exp* right;
}Exp_time;

struct exp
{
    Exp_kind kind;
     union
    {
        char* id;
        int num;
        Exp_add add;
        Exp_time time;

    }u;
};

typedef struct
{
    char* id;
    Exp* exp;
}Stm_assign;

typedef struct
{
    Exp* exp;
}Stm_print;

 struct stm
{
    Stm_kind kind;
    union
    {
        Stm_assign ass;
        Stm_print print;
    }u;
};

void print_stm(Stm* stm);
void printf_exp(Exp* exp);

void print_stm(Stm* stm)
{
    switch (stm->kind)
    {
    case ASSIGN:
        printf("%s = ", stm->u.ass.id);
        print_exp(stm->u.ass.exp);
        break;
    case PRINT:
        break;
    default:
        break;
    }

}


void print_exp(Exp* exp)
{
    switch (exp->kind)
    {
    case INT:
        printf("%d",exp->u.num);
        break;
    case ID:
        break;
    case ADD:
        print_exp(exp->u.add.left);
        printf(" + ");
        print_exp(exp->u.add.right);
        break;
    case TIME:
        break;
    default:
        printf("end\n");
        exit(0);
    }
}

int main()
{

    Exp* left = malloc(sizeof(Exp));
    left->kind = INT;
    left->u.num = 99;

    Exp* right = malloc(sizeof(Exp));
    right->kind = INT;
    right->u.num = 1;

    Exp* add = malloc(sizeof(Exp));
    add->kind = ADD;
    add->u.add.left = left;
    add->u.add.right = right;


    Stm* stm = malloc(sizeof(Stm));
    stm->kind = ASSIGN;
    stm->u.ass.id = "chuan";
    stm->u.ass.exp = add;

    print_stm(stm);
    printf("\n");

    exit(0);

    return 0;
}