https://www.nowcoder.com/questionTerminal/f0db4c36573d459cae44ac90b90c6212

#include <iostream>
#include <unordered_map>
using namespace std;

int main()
{
    string s1, s2;
    getline(cin, s1);
    getline(cin, s2);
    
    unordered_map<char, int> hash;
    for(auto ch:s2)
    {
        ++hash[ch];
    }
    string s;
    for(auto ch:s1)
    {
        if(!hash.count(ch))
        {
            s+=ch;
        }
    }
    
    cout<<s<<endl;
}

https://www.nowcoder.com/questionTerminal/459bd355da1549fa8a49e350bf3df484?

class Solution {
public:
    /**
     * 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 array int整型vector 
     * @return int整型
     */
    // 动归
    int FindGreatestSumOfSubArray(vector<int>& array) {
        // write code here
        int sum=0, result=array[0];
        for(auto num:array)
        {
            sum=max(sum+num, num);
            if(sum>result)
            {
                result=sum;
            }
        }
        
        return result;
    }
};

https://www.nowcoder.com/questionTerminal/172e6420abf84c11840ed6b36a48f8cd?

class Solution {
public:
    /**
     * 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 target int整型 
     * @param nums int整型vector 
     * @return int整型vector<vector<>>
     */
    //回溯法
    
    void backtracking(int target, vector<int>& nums, vector<vector<int>>& result, vector<int>& path, int sum, int startindex)
    {
        if(sum==target)
        {
            result.push_back(path);
            return;
        }
        
        for(int i=startindex; i<nums.size() && sum+nums[i]<=target; ++i)
        {
            sum+=nums[i];
            path.push_back(nums[i]);
            backtracking(target, nums, result, path, sum, i);
            sum-=nums[i];
            path.pop_back();
        }
    }
    vector<vector<int> > combinationCount(int target, vector<int>& nums) {
        // write code here
        vector<vector<int>> result;
        vector<int> path;
        sort(nums.begin(), nums.end());
        backtracking(target, nums, result, path, 0, 0);
        
        return result;
    }
};