字符串指定字符反转

分享一个简单的思路，代码贴上，大家一看就懂

import java.util.*;
public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     * 
     * @param s1 string字符串 
     * @param s2 string字符串 
     * @return string字符串
     */
    public String reverse (String s1, String s2) {
        // write code here
        int left = 0;
        int right = s1.length()-1;
        char[] s1Char = s1.toCharArray();
        while(left<right) {
            while (!s2.contains(String.valueOf(s1Char[left]))) {
                ++left;
            }
            while (!s2.contains(String.valueOf(s1Char[right]))) {
                --right;
            }
            char temp = s1Char[left];
            s1Char[left] = s1Char[right];
            s1Char[right] = temp;
            ++left;
            --right;
        }
        return String.valueOf(s1Char);
    }
}

 public String reverse (String s1, String s2) {
        // write code here
        String str="";
        Stack<Character> sks1=new Stack<>();
        int start=0;
        int end=s1.length()-1;
        char[] charS1=s1.toCharArray();
        while(start<end){
            if(s2.contains(String.valueOf(charS1[start]))){
                sks1.add(charS1[start]);
            }else{
                start++;
                continue;
            }
            if(s2.contains(String.valueOf(charS1[end]))){
                if(!sks1.isEmpty()){
                    char temp=charS1[end];
                    charS1[end]=sks1.pop();
                    charS1[start]=temp;
                    start++;
                    end--;
                }
            }else{
                end--;
            }
        }
        str=new String(charS1);
    return str;
    }

代码基本上就是4479的那个，不过他有部分不太对，我改了一下。

public String reverse (String s1, String s2) {
        // write code here
        char[] charS1=s1.toCharArray();
        List<Integer> index=new ArrayList();
        List<Character> str=new ArrayList();
        for(int i=0;i<s1.length();i++){
            for(int j=0;j<s2.length();j++){
                if(charS1[i]==s2.charAt(j)){
                    index.add(i);
                    str.add(charS1[i]);
                }
            }
        }
        Collections.reverse(str);
        for(int i=0;i<index.size();i++){
            charS1[index.get(i)]=str.get(i);
        }
        String a=new String(charS1);
        return a;
    }

public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param s1 string字符串
     * @param s2 string字符串
     * @return string字符串
     */
    public String reverse (String s1, String s2) {
        // write code here
        char[] s1_arr = s1.toCharArray();
        char[] s2_arr = s2.toCharArray();
 
        ArrayList<Integer> keys = new ArrayList<>();
 
        for (int i = 0; i < s1_arr.length; i++) {
            for (int j = 0; j < s2_arr.length; j++) {
                if (s1_arr[i] == s2_arr[j]) {
                    keys.add(i);
                }
            }
        }
         
        //keys里面是s1中包含在s2中的字符的索引
        //升序排列
        Collections.sort(keys);
 
        int left = 0;
        int right = keys.size() - 1;
        while (left < right) {
            char temp = s1_arr[keys.get(right)];
            s1_arr[keys.get(right)] = s1_arr[keys.get(left)];
            s1_arr[keys.get(left)] = temp;
            left++;
            right--;
        }
 
        return String.valueOf(s1_arr);
    }
}

class Solution {
public:
    string reverse(string s1, string s2) {
        unordered_set<char> us;
        for (char c : s2)
            us.insert(c);
        vector<int> indices;
        int n = s1.size();
        for (int i = 0; i < n; ++i)
            if (us.count(s1[i]) > 0)
                indices.push_back(i);
        int m = indices.size();
        int i = 0, j = m - 1;
        while (i < j) {
            swap(s1[indices[i]], s1[indices[j]]);
            ++i;
            --j;
        }
        return s1;
    }
};

import java.util.*;
import java.util.HashSet;
import java.util.Set;
 
public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     *
     *
     * @param s1 string字符串
     * @param s2 string字符串
     * @return string字符串
     */
    public String reverse (String s1, String s2) {
        // write code here
         // write code here
        Set<Character> hashSet=new HashSet<>();
        char[] c1=s1.toCharArray();
        char[] c2=s2.toCharArray();
        for (char c : c2) {
            hashSet.add(c);
        }
        int l=0,r=c1.length-1;
        while (l<r){
            while (!hashSet.contains(c1[l])){
                l++;
            }
            while (!hashSet.contains(c1[r])){
                r--;
            }
            char temp=c1[l];
            c1[l]=c1[r];
            c1[r]=temp;
            l++;
            r--;
        }
        return String.valueOf(c1);
    }
}