算法训练第八天|字符串

1. 344.反转字符串

class Solution {
public:
    void reverseString(vector<char>& s) {
        int iRight = s.size() - 1;
        int iLeft = 0;
        while(iLeft < iRight)
        {
            char cTmp = s[iLeft];
            s[iLeft] = s[iRight];
            s[iRight] = cTmp;
            iLeft++;
            iRight--;
        }
    }
};

2. 541. 反转字符串II

class Solution {
public:
    string reverseStr(string s, int k) {
        for(int i = 0;i < s.size(); i += (2 * k))
        {
            if(i+k <= s.size())
                reverse(s.begin()+i, s.begin()+i+k);
            else
                reverse(s.begin()+i, s.end());
        }
        return s;
    }
};

3. 54. 替换数字（第八期模拟笔试）

#include <iostream>
using namespace std;

int main()
{
    string s;
    while(cin >> s)
    {
        int iOldIndex = s.size() - 1;
        int iCount = 0;
        for(char i : s)
        {
            if(i > '0' && i < '9')
            {
                iCount++;
            }
        }
        s.resize(s.size() + iCount * 5);
        int iNewIndex = s.size() - 1;
        while(iOldIndex >= 0)
        {
            if(s[iOldIndex] > '0' && s[iOldIndex] < '9')
            {
                s[iNewIndex--] = 'r';
                s[iNewIndex--] = 'e';
                s[iNewIndex--] = 'b';
                s[iNewIndex--] = 'm';
                s[iNewIndex--] = 'u';
                s[iNewIndex--] = 'n';
            }
            else
            {
                s[iNewIndex--] = s[iOldIndex];
            }
            iOldIndex--;
        }
    }
    cout << s << endl;
}