SPOILER

opt(i,L) is the number of combinations of length L t...

same for me even if I set matrix_dist[I][I]=1. thank you!

Do not add spaces at the end of each test case and add new line also for the last test case

In the helper code provided by HackerRank, if you do not return a long long int, you will fail the test 11 : this is why you need to change not only the return type of the function : journeyToMoon , but also the variable that stores the result in the helper code into :

long long int result = journeyToMoon(n, astronaut);

My solution in c++

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
 
#define watch(x) cout << (#x) << " is " << (x) << endl
 
using namespace std;
 
struct mypair{
    int a;
    int b;
};
 
bool mycmp(mypair p1, mypair p2){
    return (p1.a+p1.b)>(p2.a+p2.b);
}
int main() {
ios::sync_with_stdio(false); // makes cin and cout as fast and scanf printf
#ifndef ONLINE_JUDGE

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
#include <cmath>
 
#define watch(x) cout << (#x) << " is " << (x) << endl
 
 
using namespace std;
int main() {
 
ios::sync_with_stdio(false); // makes cin and cout as fast and scanf printf
#ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
#endif
    int c;
    int test_n = 1;
    cin>>c;
    while(c--){
        int n,k,b,t;

I think the problem is the choice of the parameter : taking the greatest of tips is not the optimal choice. For example consider this case : A = [10,1 ], B = [11 ,8], X=1, Y=1 : the optimal choice is 8+11 = 19, while you algorithm : 11+1=12

This is my solution following the useful hint of Navkrishna Raghav

#include <iostream>
#include <algorithm>
#include <vector>
#include <queue>
 
#define watch(x) cout << (#x) << " is " << (x) << endl
 
using namespace std;
 
struct job{
    long int a;
    long int b;
    long long int d;
};
 
bool cmp1(job j1, job j2){
    if (j1.d == j2.d)
        return j1.a<j2.a;
    return  j1.d>j2.d ;
}
 
class cmp2{

thank you !