《Cracking the Coding Interview》——第17章：普通题——题目5

2014-04-28 22:44

题目：猜数字游戏。四个数字，每个都是0~9之间。你每猜一次，我都告诉你，有多少个位置和数字都对（全对），有多少个位置错数字对（半对）。比如“6309”，你猜“3701”，就有1全对，1半对。

解法：依照题意写就可以了。

代码：

// 17.5 I am the Master Mind. Guess the number.
// When you guessed the right number at the right position, you got a hit.
// When you guessed the right number at the wrong position, you got a pseudo-hit.
#include <cstdio>
using namespace std;

void check(int solution[], int guess[], int &hit, int &pseudo_hit)
{
    static int c[4];
    static int mark[4];
    
    int i;
    for (i = 0; i < 4; ++i) {
        c[i] = 0;
        mark[i] = 0;
    }
    
    hit = pseudo_hit = 0;
    for (i = 0; i < 4; ++i) {
        if (solution[i] == guess[i]) {
            // hit
            mark[i] = 1;
            ++hit;
        } else {
            ++c[solution[i]];
        }
    }
    for (i = 0; i < 4; ++i) {
        if (mark[i]) {
            continue;
        }
        // pseudo_hit
        if (c[guess[i]] > 0) {
            mark[i] = 2;
            --c[guess[i]];
            ++pseudo_hit;
        }
    }
}

int main()
{
    int solution[4];
    int guess[4];
    int hit, pseudo_hit;
    int i;
    
    while (scanf("%d", &solution[0]) == 1) {
        for (i = 1; i < 4; ++i) {
            scanf("%d", &solution[i]);
        }
        for (i = 0; i < 4; ++i) {
            scanf("%d", &guess[i]);
        }
        check(solution, guess, hit, pseudo_hit);
        printf("%d hit(s), %d pseudo-hit(s).\n", hit, pseudo_hit);
    }
    
    return 0;
}