SPOJ-INVERSE-SORT
Problem Algorithm: We have to generate 10! combination of " abcdefghij " by reversing and put appropriate distance from " abcdefghij " So we need key(string)->value data structure. First thing comes to our mind is map<string,int> But it uses O(logN) time to insert a value as everything is ordered here So we use unordered_map ( Normally o(1) highest o(n) barely ) After that we take 2 string input and then find the relative string S from s1->s2 and another AC!! CODE Time needed 40-45sec .