剑指 Offer 05. 替换空格

class Solution {
public:
    string replaceSpace(string s) {
        string res;
        for(auto e : s)
        {
            if(e == ' ')
            {
                res+='%';
                res+='2';
                res+='0';
            }
            else
                res+=e;
        }
        return res;
    }
};

 剑指 Offer 58 - II. 左旋转字符串

class Solution {
public:
    string reverseLeftWords(string s, int n) {
        int size = s.size();
        int div = (size-n)%size;
        reverse(s.begin(), s.end());
        reverse(s.begin(), s.begin()+div);
        reverse(s.begin()+div, s.end());
        return s;
    }
};

 剑指 Offer 03. 数组中重复的数字

class Solution {
public:
    int findRepeatNumber(vector<int>& nums) {
        map<int,int>mp;
        for(auto e : nums)
        {
            if(mp[e]==1)
                return e;
            mp[e]++;
        }
        return -1;
    }
};

剑指 Offer 53 - I. 在排序数组中查找数字

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int res = 0;
        int idx = getFirstTargetIndex(nums, target);
        if (idx == -1) return res;
        for (int i = idx; i < nums.size() && nums[i] == target; i++) res++;
        return res;
    }
private:
    int getFirstTargetIndex(vector<int>& nums, int target) {
        int left = 0, right = nums.size() - 1;
        int res = -1;
        while (left <= right) {
            int mid = left + (right - left) / 2;
            if (nums[mid] > target) right = mid - 1;
            else if (nums[mid] < target) left = mid + 1;
            else {
                res = mid;
                right = mid - 1;
            }
        }
        return res;

    }
};

剑指 Offer 53 - II. 0～n-1中缺失的数字

class Solution {
public:
    int missingNumber(vector<int>& nums) {
        for(int i = 0; i < nums.size(); i++)
        {
            if(nums[i]!=i)
                return i;
        }
        return nums.back()+1;
    }
};