problem : SUMTRIAN , doubt about memory allocation

help
,
1

solution : CodeChef: Practical coding for everyone
works , and has fixed memory allocation, but the same logic in solution : CodeChef: Practical coding for everyone doesnt work and its dynamically allocated.

can someone please explain me why?

2

For one thing, you’re using the wrong kind of delete - if you’re delete’ing a dynamically-allocated array, you use:

delete[]

instead of:

delete

You’re also not initialising your dynamic arrays:

but perhaps this doesn’t matter - it’s hard to tell.

You’re also leaking memory everywhere :stuck_out_tongue:

I’d just use vectors.

Edit:

You also have out-of-bounds accesses on these lines:

 dp[i][j] = arr[i][j] +dp[i-1][j-1];

  dp[i][j]= arr[i][j] + max(dp[i-1][j], dp[i-1][j-1]);

on the sample testcase (exposed by using vectors and the gcc debug mode).

Oh: also shows up in your AC solution:

[simon@simon-laptop][09:23:26]
[~/devel/hackerrank/otherpeoples]>./compile-latest-cpp.sh 
Compiling xym991-SUMTRIAN-ac.cpp
Executing command:
  g++ -std=c++17 xym991-SUMTRIAN-ac.cpp -O3 -g3 -Wall -Wextra -Wconversion -DONLINE_JUDGE -D_GLIBCXX_DEBUG    -fsanitize=undefined -ftrapv
Successful
[simon@simon-laptop][09:23:28]
[~/devel/hackerrank/otherpeoples]>echo "2
3
1
2 1
1 2 3
4
1
1 2
4 1 2
2 3 1 1
" | ./a.out
xym991-SUMTRIAN-ac.cpp:36:63: runtime error: index -1 out of bounds for type 'int [100]'
5
9
3

ahhh… i see . thank you so much dude.

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