a291: nAnB problem. FYI: https://yunlinsong.blogspot.com/2016/02/a291-nanb-problem.html

a291.cpp

#include <cstdio>
#include <iostream>

using namespace std;

int main() {
    int CNT = 4;
	int answer[CNT];
	int guess[CNT];
	int idx = 0;
    int round = 0;

	while( scanf("%d %d %d %d", &answer[0], &answer[1], &answer[2], &answer[3])!=EOF ) {
        scanf("%d", &round);

        int a[round] = { 0 };
        int b[round] = { 0 };

        idx = 0;
        while( idx < round ) {
            int guessIdx = 0;
            int found[CNT] = { 0 };

            while( guessIdx < CNT ) {
                scanf("%d", &guess[guessIdx]);

                // How many A.
                if(guess[guessIdx] == answer[guessIdx]) {
                    a[idx]++;
                    found[guessIdx] = 1;
                } else {
                    found[guessIdx] = 0;
                }

                guessIdx++;
            }

            // How Many B.
            for( guessIdx = 0; guessIdx < CNT; guessIdx++) {
                if( found[guessIdx] != 1 )
                for(int answerIdx = 0; answerIdx < CNT; answerIdx++) {
                    if( found[answerIdx] == 0 && (guess[guessIdx] == answer[answerIdx]) && guessIdx != answerIdx ) {
                        b[idx]++;
                        found[answerIdx] = 2;
                        break;
                    }
                }
            }

            idx++;
        }

        idx = 0;
        while( idx < round ) {
            printf("%dA%dB\n", a[idx], b[idx]);
            idx++;
        }
	}
	return 0;
}