Implementation of diff functions-LCs variants

Where did I go for a written test yesterday? I met a familiar command (diff -- below UBUNTU) that can compare strings, that is, according to the longest public substring problem, if a contains characters not in B, the output format is as follows (-Ch). If a does not, B can output the following format (+ CH ).

 

#include <iostream>#include <cstring>#include <vector>using namespace std;string LCS(string &s1, string &s2){    int row = s1.size();    int col = s2.size();    string table[row + 1][col + 1];    char rowChar[row + 1];    char colChar[col + 1];    int cnt = 0;    rowChar[0] = colChar[0] = ‘\0‘;    for(int i = row - 1, cnt = 1; i >= 0; i--, cnt++)    {        rowChar[cnt] = s1[i];    }    for(int i = col - 1, cnt = 1; i >= 0; i--, cnt++)    {        colChar[cnt] = s2[i];    }    char ch1, ch2;    string str1, str2;    for(int i = 1; i <= row; i++)    {        for(int j = 1; j <= col; j++)        {            ch1 = rowChar[i];            ch2 = colChar[j];            if(ch1 == ch2)                table[i][j] = ch1 + table[i - 1][j - 1];            else            {                str1 = table[i - 1][j];                str2 = table[i][j - 1];                if(str1.size() == str2.size())                    table[i][j] = str1 < str2 ? str2 : str1;                else                    table[i][j] = str1.size() < str2.size() ? str2 : str1;            }        }    }    return table[row][col];}void showDiff(string &s1, string &s2, string sub, vector<string> &ret){    cout << "Sub = " << sub << endl;    int len1 = s1.size();    int len2 = s1.size();    for(int i = 0, j = 0; i < len1; i++)    {        if(s1[i] != sub[j])        {            string str;            str.push_back(‘-‘);            str.push_back(s1[i]);            ret.push_back(str);        }        else            j++;    }    for(int i = 0, j = 0; i < len2; i++)    {        if(s2[i] != sub[j])        {            string str;            str.push_back(‘+‘);            str.push_back(s2[i]);            ret.push_back(str);        }        else            j++;    }}int main(){    string str1, str2;    cin >> str1 >> str2;    string retSub = LCS(str1, str2);    vector<string> ret;    showDiff(str1, str2, retSub, ret);    vector<string>::iterator iter;    for(iter = ret.begin(); iter != ret.end(); iter++)        cout << *iter << endl;    return 0;}

 

Implementation of diff functions-LCs variants