Description

 The x97 CPU has 4 32 bits registers, r0, r1, r2, and r3, whose initial values are all zeros. The CPU has 2 kinds of instructions, MOV and ADD, whose formats are specified as follows.

1.      MOV , : assign constant C to register 1.

2.      MOV , : copy the content of register 2 to register 1.

3.      ADD , : add the value of register 1 and constant C, and save the result to register 1.

4.      ADD , : add the value of register 1 and the value of register 2, and save the result to register 1.

 

  

Hint:
You can use the following code to get the input and to print the output.
#include 
#include 
#include 
enum code {MOV, ADD};
enum op_type {REG, CONST};
typedef struct INST {
    enum code opcode;
    enum op_type op1;
    int operand1_value;
    enum op_type op2;
    int operand2_value;
    struct INST* next;
} INST;
/* read input from stdin. */
INST* readInput(){
    char opc[10], op1[10], op2[10];
    int ns=0, c;
    INST *head=0, *curr=0;
    ns = scanf("%s %s %d ", opc, op1, &c);
    while(ns > 0) {
        /* allocate a storage for an instruction */
        if (head == 0){
            head = (INST*) malloc(sizeof(INST));
            curr = head;
            curr->next = 0;
        } else {
            curr->next = (INST*) malloc(sizeof(INST));
            curr = curr->next;
            curr->next = 0;
        }
       /* set the content of the instruction.*/
        /* opcode */
        if (strcmp(opc, "MOV")==0)
            curr->opcode = MOV;
        else if (strcmp(opc, "ADD")==0)
            curr->opcode = ADD;
        /* Since op1 is always a register, read its id.*/
        curr->op1 = REG;
        curr->operand1_value = op1[1]-'0';
        /* read operand 2.*/
        if (ns == 2){  /* operand 2 is a register*/
            scanf("%s ", op2);
            curr->op2 = REG;
            curr->operand2_value = op2[1] -'0';
        } else if (ns == 3) { /* operand 2 is a constant.*/
            curr->op2 = CONST;
            curr->operand2_value = c;
        }
        /* get next one*/
        ns = scanf("%s %s %d ", opc, op1, &c);
    }
    return head;
}

 

Input

 The input is a list of instructions.

Output

 The output is the values of all register in the order of r0, r1, r2, and r3.

Use %4d for each resgister and print a newline in the end.

Sample Input  Download

Sample Output  Download

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