Algorithm
Problem link- https://www.spoj.com/problems/CPRMT/
CPRMT - Common Permutation
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.
Example
Sample input: pretty women walking down the street Sample output: e nw et
Code Examples
#1 Code Example with C++ Programming
Code -
C++ Programming
#include<bits/stdc++.h>
using namespace std;
#define LL long long int
#define LD long long double
int main(){
while(!cin.eof()){
string A,B;
getline(cin,A);
getline(cin,B);
sort(A.begin(),A.end());
sort(B.begin(),B.end());
int l1=A.length();int l2 =B.length();
if(l1>l2){
string temp = A;
A=B;B=temp ;
int temp1 =l1;
l1= l2;
l2= temp1;
//swaping integers
}
if(A[0]>B[l2-1]){
cout<<"\n";
continue;
}
string result;
int i = 0,m = 0 ;
while(i<l1 && m<l2){
int flg=0;
int j = m;
while(j<l2){
if(A[i]==B[j]){
result+=A[i];
flg=1;
m=j;
break;
}
j++;
}
if(flg==1){m++;}
i++;
}
result+="\n";
cout<<result;
}
}Input
women
walking
down
the
street
Output
nw
et
Demonstration
SPOJ Solution-Common Permutation-Solution in C, C++, Java, Python