Algorithm
Problem Name: 771. Jewels and Stones
You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Each character in stones is a type of stone you have. You want to know how many of the stones you have are also jewels.
Letters are case sensitive, so "a" is considered a different type of stone from "A".
Example 1:
Input: jewels = "aA", stones = "aAAbbbb" Output: 3
Example 2:
Input: jewels = "z", stones = "ZZ" Output: 0
Constraints:
1 <= jewels.length, stones.length <= 50jewelsandstonesconsist of only English letters.- All the characters of
jewelsare unique.
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
class Solution {
public:
int numJewelsInStones(string J, string S) {
int count = 0;
unordered_set < char>s;
for(char c: J) s.insert(c);
for(char c: S) if(s.count(c)) count++;
return count;
}
};
Input
Output
#2 Code Example with Java Programming
Code -
Java Programming
class Solution {
public int numJewelsInStones(String J, String S) {
Set set = new HashSet<>();
for (char c : J.toCharArray()) {
set.add(c);
}
int count = 0;
for (char c : S.toCharArray()) {
if (set.contains(c)) {
count++;
}
}
return count;
}
}
Input
Output
#3 Code Example with Javascript Programming
Code -
Javascript Programming
const numJewelsInStones = function(J, S) {
if(J == null || J === '' || S == null || S === '') return 0
const m = new Set(J)
let res = 0
for(let e of S) {
if(m.has(e)) res++
}
return res
};
Input
#4 Code Example with Python Programming
Code -
Python Programming
class Solution:
def numJewelsInStones(self, J, S):
sj = set(J)
return sum(s in sj for s in S)
Input
#5 Code Example with C# Programming
Code -
C# Programming
using System.Collections.Generic;
namespace LeetCode
{
public class _0771_JewelsAndStones
{
public int NumJewelsInStones(string J, string S)
{
var map = new Dictionary < char, int>();
foreach (var ch in J)
map.Add(ch, 0);
int result = 0;
foreach (var ch in S)
if (map.ContainsKey(ch)) result++;
return result;
}
}
}
Input
Output