Algorithm
Problem Name: 299. Bulls and Cows
You are playing the Bulls and Cows game with your friend.
You write down a secret number and ask your friend to guess what the number is. When your friend makes a guess, you provide a hint with the following info:
- The number of "bulls", which are digits in the guess that are in the correct position.
- The number of "cows", which are digits in the guess that are in your secret number but are located in the wrong position. Specifically, the non-bull digits in the guess that could be rearranged such that they become bulls.
Given the secret number secret and your friend's guess guess, return the hint for your friend's guess.
The hint should be formatted as "xAyB", where x is the number of bulls and y is the number of cows. Note that both secret and guess may contain duplicate digits.
Example 1:
Input: secret = "1807", guess = "7810" Output: "1A3B" Explanation: Bulls are connected with a '|' and cows are underlined: "1807" | "7810"
Example 2:
Input: secret = "1123", guess = "0111" Output: "1A1B" Explanation: Bulls are connected with a '|' and cows are underlined: "1123" "1123" | or | "0111" "0111" Note that only one of the two unmatched 1s is counted as a cow since the non-bull digits can only be rearranged to allow one 1 to be a bull.
Constraints:
1 <= secret.length, guess.length <= 1000secret.length == guess.lengthsecretandguessconsist of digits only.
Code Examples
#1 Code Example with C Programming
Code -
C Programming
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#define min(a,b) ((a) < (b)?(a):(b))
char* getHint(char* secret, char* guess) {
char hashs[10] = { 0 };
char hashg[10] = { 0 };
int len = strlen(secret);
int bulls = 0, cows = 0;
int i;
for (i = 0; i < len; i++) {
if (secret[i] == guess[i]) {
bulls++;
}
else {
hashs[secret[i] - '0']++;
hashg[guess[i] - '0']++;
}
}
for (i = 0; i < 10; i++) {
cows += min(hashs[i], hashg[i]);
}
char *hint = (char *)malloc(5);
sprintf(hint, "%dA%dB", bulls, cows);
hint[5] = '\0';
return hint;
}
int main() {
assert(strcmp(getHint("1807", "7810"), "1A3B") == 0);
assert(strcmp(getHint("1234", "0111"), "0A1B") == 0);
assert(strcmp(getHint("1122", "2211"), "0A4B") == 0);
printf("all tests passed!\n");
return 0;
}
Input
Output
#2 Code Example with Javascript Programming
Code -
Javascript Programming
const getHint = function(secret, guess) {
let bulls = 0
let cows = 0
const h = {}
for(let i = 0, len = secret.length; i < len; i++) {
if(secret[i] === guess[i]) {
bulls++
} else {
if(!h.hasOwnProperty(secret[i])) h[secret[i]] = 0
h[secret[i]]++
}
}
for(let i = 0, len = secret.length; i < len; i++) {
if(secret[i] !== guess[i]) {
if(h.hasOwnProperty(guess[i]> && h[guess[i]] > 0) {
cows++
h[guess[i]]--
}
}
}
return `${bulls}A${cows}B`
};
Input
Output
#3 Code Example with Python Programming
Code -
Python Programming
class Solution:
def getHint(self, secret, guess):
s, g, a, b = collections.defaultdict(int), collections.defaultdict(int), 0, 0
for i in range(len(secret)):
if secret[i] == guess[i]: a += 1; continue
if s[guess[i]] > 0: b, s[guess[i]] = b + 1, s[guess[i]] - 1
else: g[guess[i]] += 1
if g[secret[i]] > 0: b, g[secret[i]] = b + 1, g[secret[i]] - 1
else: s[secret[i]] += 1
return "%dA%dB" % (a, b)
Input
Output
#4 Code Example with C# Programming
Code -
C# Programming
namespace LeetCode
{
public class _0299_BullsAndCows
{
public string GetHint(string secret, string guess)
{
var counts = new int[10];
foreach (var ch in secret)
counts[ch - '0']++;
int a = 0, b = 0;
for (int i = 0; i < guess.Length; i++)
{
if (guess[i] == secret[i])
{
a++;
if (counts[guess[i] - '0'] > 0)
counts[guess[i] - '0']--;
else
b--;
continue;
}
if (counts[guess[i] - '0'] > 0)
{
b++;
counts[guess[i] - '0']--;
}
}
return $"{a}A{b}B";
}
}
}
Input
Output