#力扣：771. 宝石与石头@FDDLC

771. 宝石与石头 - 力扣（LeetCode）

一、Java

class Solution {
    public int numJewelsInStones(String jewels, String stones) {
        int[] isJewel = new int['z' + 1];
        for (int i = jewels.length() - 1; i >= 0; i--) isJewel[jewels.charAt(i)] = 1;
        int cnt = 0;
        for (int i = stones.length() - 1; i >= 0; i--) cnt += isJewel[stones.charAt(i)];
        return cnt;
    }
}

二、C++

#include 
 
using namespace std;
 
class Solution {
public:
    int numJewelsInStones(string jewels, string stones) {
        int isJewel['z' + 1] = {};
        for (char c: jewels) isJewel[c] = 1;
        int cnt = 0;
        for(char c: stones) cnt += isJewel[c];
        return cnt;
    }
};

三、Python

class Solution:
    def numJewelsInStones(self, jewels: str, stones: str) -> int:
        isJewel = set(jewels)
        cnt = 0
        for c in stones:
            if c in isJewel:
                cnt += 1
        return cnt

四、JavaScript

var numJewelsInStones = function(jewels, stones) {
    let isJewel = new Set(jewels);
    let cnt = 0;
    for(let c of stones) {
        if(isJewel.has(c)) cnt++;
    }
    return cnt;
};

五、Go

package main
func numJewelsInStones(jewels string, stones string) int {
	var isJewel ['z' + 1]int
	for _, c := range jewels {
		isJewel[c] = 1
	}
	cnt := 0
	for _, c := range stones {
		cnt += isJewel[c]
	}
	return cnt
}