771宝石与石头

思路与结果

代码

思路1

package Day1_3_31.L771;
import java.util.Scanner;

public class Main1 {
public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
String str1 = sc.next();
String str2 = sc.next();
int n = num(str1,str2);
System.out.println(n);
}

public static int num(String J, String S){
char[] chsJ = J.toCharArray();
char[] chsS = S.toCharArray();

int count = 0;

for (int i = 0; i < chsJ.length; i++) {
for (int i1 = 0; i1 < chsS.length; i1++) {
if (chsJ[i] == chsS[i1]){
count++;
}
}
}
return count;
}
}

思路2

package Day1_3_31.L771;
import java.util.HashMap;
import java.util.Scanner;

public class Main2 {
public static void main(String[] args) {

Scanner sc = new Scanner(System.in);
String str1 = sc.next();
String str2 = sc.next();
int n = num(str1,str2);
System.out.println(n);
}

public static int num(String J, String S){
char[] chsJ = J.toCharArray();
char[] chsS = S.toCharArray();

HashMap<Character, Integer> map = new HashMap<>();

for (int i = 0; i < chsS.length; i++) {
if (map.containsKey(chsS[i])){
map.put( chsS[i], map.get(chsS[i]) + 1);
}else{
map.put(chsS[i], 1);
}
}
int count = 0;

for (int i = 0; i < chsJ.length; i++) {
if (map.containsKey(chsJ[i])){
count += map.get(chsJ[i]);
}
}
return count;

}
}