還是覺得有必要堅持刷leetcode 在這裏打卡。 加油。 這是第一遍 很慚愧。做這一行這麽久 才開始刷力扣。但是開始了總是好的。盡管代碼醜,但是至少都是能通過的吧。

堅持下去！

定個目標 如果不加班就要刷 一道題。 每個周至少兩道！ 堅持堅持堅持

1、 Total Accepted: 159385 Total Submissions: 822358 Difficulty: Medium

Given an array of integers, find two numbers such that they add up to a specific target number.

The function twoSum should return indices of the two numbers such that they add up to the target, where index1 must be less than index2. Please note that your returned answers (both index1 and index2) are not zero-based.

You may assume that each input would have exactly one solution.

Input: numbers={2, 7, 11, 15}, target=9

My Answer：

class Solution {
public:
    vector<int> twoSum(vector<int>& nums, int target) {
        
        int temp,temp_j;
        map<int,int> num_map;
        vector<int> ret;
        for(int i=0;i<nums.size();++i){
            
            temp 
 
= nums.at(i);
            temp_j = target-temp;
            if( num_map.count(temp_j)){
            
                if(i > num_map[temp_j]){
                    ret.push_back(num_map[temp_j]+1);
                    ret.push_back(i+1);
                    return ret;
                }
            }
            num_map.insert( pair<int,int>(temp,i) );
        }
    }
};

2、You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a linked list.

Input: (2 -> 4 -> 3) + (5 -> 6 -> 4)
Output: 7 -> 0 -> 8

My Answer:

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* addTwoNumbers(ListNode* l1, ListNode* l2) {
      
        ListNode *t_l1 = l1;
        ListNode *t_l2 = l2;
        ListNode *p=NULL;
        ListNode *l = t_l1;
        
        bool inc_ = false;
        while( t_l1!=NULL || t_l2!=NULL ){
            if(t_l1){
                p = t_l1;
            }else{            
                if(p){
                    p->next = t_l2;
                }
                p = t_l2;
            }
                
            if(t_l1&&t_l2){
                t_l1->val = t_l1->val+t_l2->val;                
                if( t_l1->val>=10 ){
                    inc_ = true;
                    t_l1->val = t_l1->val%10;          
                }
                t_l1 = t_l1->next;
                t_l2 = t_l2->next;
            }else if(t_l1){                
                if( t_l1->val>=10 ){
                    inc_ = true;
                    t_l1->val = t_l1->val%10;
                }
                t_l1 = t_l1->next;
            }else if(t_l2){                
                t_l1 = t_l2;                
                if( t_l1->val>=10 ){
                    inc_ = true;
                    t_l1->val = t_l1->val%10;
                }
                t_l1 = t_l1->next;
                t_l2 = NULL;
            }
            
            if( inc_ ){
                if(!t_l1){
                    t_l1 = new ListNode(0);
                    p->next = t_l1;
                }
                
                t_l1->val = t_l1->val+1;
                inc_ = false;
            }
            
        }
     　　return l;
    }
};

LeetCode (Two Sum & Add Two nums)