LeetCode 451. Sort Characters By Frequency [Medium]

题目来源:https://leetcode.com/problems/sort-characters-by-frequency

题目难度:Medium

解答1[Java]:

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class Solution {
public String frequencySort(String s) {
int[] map = new int[128];
for (char c : s.toCharArray()) {
map[c]++;
}
char[] res = new char[s.length()];
int pos = 0;
while (pos < s.length()) {
char max = 0;
for (char c = 0; c < map.length; c++) {
if (map[c] > map[max])
max = c;
}
int repeat = map[max];
for (int i = 0; i < repeat; i++) {
res[pos++] = max;
map[max]--;
}
}
return new String(res);
}
}