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// 401. Binary Watch
#include "leetcode.h"
/*
* a binary watch has 4 leds on the top to represent the hours (0 - 11) and 6
* leds on the bottom to represent the minutes (0 - 59). each led represents a 0
* or one, with the least siginificant bit on the right. given an integer
* 'turnedOn' which represents the number of leds that are currently on, return
* all possible times the watch could represent. you may return the answer in
* any order.
*/
char **readBinaryWatch(int turnedOn, int *returnSize) {
char **ans = (char **)malloc(190 * sizeof(char *));
*returnSize = 0;
for (int h = 0; h < 12; h++)
for (int m = 0; m < 60; m++) {
int total = __builtin_popcount(h) + __builtin_popcount(m);
if (total == turnedOn) {
ans[*returnSize] = (char *)malloc(8 * sizeof(char));
snprintf(ans[*returnSize], 8, "%d:%02d", h, m);
(*returnSize)++;
}
}
return ans;
}
int main() {
int rs1, rs2;
char **rbw1 = readBinaryWatch(1, &rs1);
char **rbw2 = readBinaryWatch(9, &rs2);
for (int i = 0; i < rs1; i++)
printf(
"%s ",
rbw1[i]); // expect: 0:01,0:02,0:04,0:08,0:16,0:32,1:00,2:00,4:00,8:00
printf("\n");
for (int i = 0; i < rs2; i++)
printf("%s ", rbw2[i]); // expect: null
printf("\n");
for (int i = 0; i < rs1; i++)
free(rbw1[i]);
free(rbw1);
for (int i = 0; i < rs2; i++)
free(rbw2[i]);
free(rbw2);
}
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