版权声明:本文为博主原创文章,未经博主允许不得转载。 https://blog.csdn.net/qq_32767041/article/details/86499434
Description
牛客网 2018校招真题 DNA序列
题目描述真的令人费解
Solving Ideas
题目中所说的DNA片段有:
长度为1的DNA片段:‘A’, ‘C’, ‘G’, ‘T’, 共Math.pow(4, 1)=4个
长度为2的DNA片段:‘AA’, ‘CC’, ‘GG’, ‘TT’, ‘AC’, ‘CA’, ‘AG’,‘GA’, ‘AT’, ‘TA’,‘CG’, ‘GC’, ‘CT’,‘TC’, ‘GC’, ‘CG’, 共Math.pow(4, 2)=16个
…
长度为n的DNA片段:…
求最短没有出现在字符串s中的DNA片段的长度
Time complexity :
Space complexity :
Solution
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
/**
* @author wylu
*/
public class Main {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int[] counts = new int[26];
for (char ch : br.readLine().toCharArray()) counts[ch - 'a']++;
int k = Integer.parseInt(br.readLine());
while ((k--) != 0) {
//每次最大值减1,最终可使总价值达到最小
int maxIdx = 0;
for (int i = 1; i < 26; i++) {
if (counts[i] > counts[maxIdx]) maxIdx = i;
}
counts[maxIdx]--;
}
int res = 0;
for (int i = 0; i < 26; i++) res += counts[i] * counts[i];
System.out.println(res);
}
}