我剛學程式老師給很難的題目，希望高手可以幫我解答，謝謝

請撰寫一個猜數字遊戲。電腦產生之數字(被猜的數字)為隨機產生，且必須三個數字不同，輸入的數(玩家猜測的數字)亦要檢測是否三個數值不同。玩家一回合可以猜五次數字，若輸入-1結束遊戲。

NOTE:

(1)    若電腦當回合產生數字為211，因後面兩數相同，必須重新產生。

(2)    若玩家輸入211，因後面兩數相同，必須重新產生。

(3)    一回合僅可以猜測五次。

(4)    輸入 -1 結束遊戲。

//A game to guess the number which generated by the computer,
//each round user will input a number, if that number match the number generated by computer, user will win.
//If after 5 times user still can't guess the number, user will lose.
//If user input -1 the program will end here.
//user can not input the same numbers like 111,222,...or 211,311,... or 112,113... It is all wrong to input
//If the number generated is the same numbers like 111,222,...or 211,311,... or 112,113... It will auto change different numbers

#include<iostream>
#include<cstdlib>
#include<ctime>

using namespace std;

int main()
{
    int ANS,Input,i;
    int a,b,c;
    int x,y,z;
    int A=0;
    int B=0;
    int times = 0;


    while(Input!=-1){ //if user input -1, it will break the while loop and end the program


         srand( time(NULL) ); //generate a random number after a round
         ANS = rand()%(999-100+1)+100; //range of numbers generated by computer from 100 to 999

        do //check the ANS if they have the same number
        {
            z = ANS % 10; //3rd
            y = (ANS % 100 - z) / 10; //2nd
            x = ANS / 100; //1st

        }
        while(x==y || x==z || y==z);{

       

        for(i=1;i<=5;i++){ //it is maximum 5 times for user to guess the number generated by computer

            cout << i << " : please input the number: ";
            cin >> Input; //user input the number they guess here

            c = Input%10; //3rd
            b = (Input%100-a)/10; //2nd
            a = Input/100; //1st

            if( Input == -1 ) //if user input -1, it will break the for loop
            {
                break;
            }
            //check the Input number and ANS, if they have the same number with the same position then A+1; else B+1
                if(a==x){A++;}
                if(a==y){B++;}
                if(a==z){B++;}

                if(b==x){B++;}
                if(b==y){A++;}
                if(b==z){B++;}

                if(c==x){B++;}
                if(c==y){B++;}
                if(c==z){A++;}


            cout << "Result" << i <<" : "<< A <<"A"<< B <<"B" << endl << endl;

             if(a==c||a==b||c==b) //check the Input number and ANS if they the same, output you are wrong
            {
                cout << "You input a wrong number. Please input again."<<endl<<endl;
            }

            if( Input == ANS || A==3 ) //if user input the number match the number generated by computer, they will win and the program will show user the answer
            {
                cout << "You win!! " << endl << endl;
                break;
            }

            if( i == 5) // if user can't input the correct number after 5 times, they will lose and the program will show user the answer
            {
                cout << "you are a loser "  << endl << endl;
                break;
            }

        }
        return 0;
    }
    }
}


請問我這樣寫為什麼不能輸入5次每round, 然後判斷AB是錯嗎， 請高手幫我改一改。

非常感謝！！！