HashMap 解决计算字符个数问题
计算字符个数
http://www.nowcoder.com/questionTerminal/a35ce98431874e3a820dbe4b2d0508b1
用了hashmap来做。当然还是推荐(str.length()-str.replaceAll(s,"").length()
import java.util.*;
public class Main{
public static void main(String[] args){
Scanner sc = new Scanner(System.in);
String input = sc.next();
String upperStr = input.toUpperCase();
char c = sc.next().toUpperCase().charAt(0);
int ans = checkNum(upperStr, c);
System.out.print(ans);
}
private static int checkNum(String str, char c){
int res = 0;
int len = str.length();
HashMap<Character, Integer> map= new HashMap<> ();
for(int i = 0; i < len; i++){
char cur = str.charAt(i);
map.put(cur, map.getOrDefault(cur, 0)+1);
}
if(!map.containsKey(c)){
return res;
} else {
res = map.get(c);
return res;
}
}
}
阿里云工作强度 238人发布
查看21道真题和解析