## Wednesday, March 16, 2011

### UVa_10252_Common_Permutation.cpp

poj2629, uva10252,

## Problem:

Problem G
Common Permutation
Input: standard input
Output: standard output
Time Limit: 4 seconds
Memory Limit: 32 MB

Given two strings of lowercase letters, a and b, print the longest string x of lowercase letters such that there is a permutation of x that is a subsequence of a and there is a permutation of x that is a subsequence of b.

Input
Input file contains several lines of input. Consecutive two lines make a set of input. That means in the input file line 1 and 2 is a set of input, line 3 and 4 is a set of input and so on. The first line of a pair contains a and the second contains b. Each string is on a separate line and consists of at most 1000 lowercase letters.

Output
For each set of input, output a line containing x. If several x satisfy the criteria above, choose the first one in alphabetical order.

Sample Input:
`pretty`
`women`
`walking`
`down`
`the`
`street`
` `
Sample Output:
e
nw
et

(World Finals Warm-up Contest, Problem Source: University of Alberta Local Contest)

## Solution:

Just take care of input data, there is a blank line between each string.

## Source Code:

//Wed Mar 16 22:14:38 CDT 2011
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>

using namespace std;

string solve(string s1, string s2)
{
string str = "";
for (int i = 0; i < s1.size(); i++)
{
if (isalpha(s1[i]) == false) continue;
int found = s2.find(s1[i]);
if (found != string::npos)
{
str += s1[i];
s2[found] = '.';
}
}
std::sort(str.begin(), str.end());
return str;
}

int main(int argc, char* argv[])
{
//freopen("input.in", "r", stdin);
//freopen("output.out", "w", stdout);
char s1, s2;
while (gets(s1))
{
//getchar();
gets(s2);
//getchar();
cout << solve(string(s1), string(s2)) << endl;
}
//fclose(stdin);
//fclose(stdout);
return 0;
}