LeetCode（剑指 Offer）- 45. 把数组排成最小的数

Posted 2022-07-16 放羊的牧码

题目链接：点击打开链接

题目大意：略

解题思路

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AC 代码

• Java

// 解决方案(1)
class Solution 
    public String minNumber(int[] nums) 
        String[] strs = new String[nums.length];
        for(int i = 0; i < nums.length; i++)
            strs[i] = String.valueOf(nums[i]);
        quickSort(strs, 0, strs.length - 1);
        StringBuilder res = new StringBuilder();
        for(String s : strs)
            res.append(s);
        return res.toString();
    
    void quickSort(String[] strs, int l, int r) 
        if(l >= r) return;
        int i = l, j = r;
        String tmp = strs[i];
        while(i < j) 
            while((strs[j] + strs[l]).compareTo(strs[l] + strs[j]) >= 0 && i < j) j--;
            while((strs[i] + strs[l]).compareTo(strs[l] + strs[i]) <= 0 && i < j) i++;
            tmp = strs[i];
            strs[i] = strs[j];
            strs[j] = tmp;
        
        strs[i] = strs[l];
        strs[l] = tmp;
        quickSort(strs, l, i - 1);
        quickSort(strs, i + 1, r);
    


// 解决方案(2)
class Solution 
    public String minNumber(int[] nums) 
        String[] strs = new String[nums.length];
        for(int i = 0; i < nums.length; i++)
            strs[i] = String.valueOf(nums[i]);
        Arrays.sort(strs, (x, y) -> (x + y).compareTo(y + x));
        StringBuilder res = new StringBuilder();
        for(String s : strs)
            res.append(s);
        return res.toString();
    

• C++

// 解决方案(1)
class Solution 
public:
    string minNumber(vector<int>& nums) 
        vector<string> strs;
        for(int i = 0; i < nums.size(); i++)
            strs.push_back(to_string(nums[i]));
        quickSort(strs, 0, strs.size() - 1);
        string res;
        for(string s : strs)
            res.append(s);
        return res;
    
private:
    void quickSort(vector<string>& strs, int l, int r) 
        if(l >= r) return;
        int i = l, j = r;
        while(i < j) 
            while(strs[j] + strs[l] >= strs[l] + strs[j] && i < j) j--;
            while(strs[i] + strs[l] <= strs[l] + strs[i] && i < j) i++;
            swap(strs[i], strs[j]);
        
        swap(strs[i], strs[l]);
        quickSort(strs, l, i - 1);
        quickSort(strs, i + 1, r);
    
;

// 解决方案(2)
class Solution 
public:
    string minNumber(vector<int>& nums) 
        vector<string> strs;
        string res;
        for(int i = 0; i < nums.size(); i++)
            strs.push_back(to_string(nums[i]));
        sort(strs.begin(), strs.end(), [](string& x, string& y) return x + y < y + x; );
        for(int i = 0; i < strs.size(); i++)
            res.append(strs[i]);
        return res;
    
;