Here you will find solutions of many problems on spoj. If you want solution of some problem which is not listed in blog or have doubt regarding any spoj problem (which i have solved) or any programming concept (data structure) you can mail me @
And my humble request to you all that don't copy the code only try to understand the logic and algorithm behind the code. I have started this because if you tried as hard as you can and still can't find any solution to the problem then you can refer to this.
You can read my answer how to start competitive programming CLICK HERE

Sunday, September 27, 2015



Given below code is for AIBHOP spoj or aibohphobia spoj.

Name :- Nishant Raj
Email :-
College :- Indian School of Mines
Branch :- Computer Science and Engineering
Time :- 27 September 2015 (Sunday) 22:47
#include <bits/stdc++.h>
using namespace std;
int dp[6101][6101];
char s[6109];
int rec( int i , int j){
    if(i > j)
        return INT_MAX;
    if(i == j)
        return 0;
    if(i == j -1 )
        return s[i] == s[j] ? 0 : 1;
    if(dp[i][j] != -1)
        return dp[i][j];
    if(s[i] == s[j]){
        return dp[i][j] = rec(i+1 , j-1);
    else {
        return dp[i][j] = min(rec(i+1 , j) , rec(i , j-1)) + 1;
int main(){
    int t;
    scanf("%d", &t);
        memset(dp , -1 , sizeof dp);
        int len = strlen(s);
        printf("%d\n",rec(0 , len-1));
    return 0;