Simplify variable tracking across functions and loops!

int mat[3][5]{};
vector<int> v;
for (int i = 1; i <= 3; i++)
{
    v.push_back(i * i);
    debug(i, v);
}
debug(mat);

// stderr
23: [i = 1 || v = {1}]
23: [i = 2 || v = {1,4}]
23: [i = 3 || v = {1,4,9}]
25: [mat = 
~~~~~
0 {0,0,0,0,0}
1 {0,0,0,0,0}
2 {0,0,0,0,0}
~~~~~
]

This template supports datatypes such as:

• Primitive: int, char, bool, long long int etc.
• STL: pair, tuple, vector, set, oset, map, omap,stack, queue, priority_queue, bitset etc.
• Arrays of all datatypes: int arr[], bool arr[], vector<int> adj[] etc.
• Matrix: int dp[100][200], vector<vector<bool>> vis(100, vector<bool> (200, 0)) etc.
• Arrays that have been decayed or declared at runtime int arr[n].
• Rvalue Literals like "Hello", false, 'z', isSafe(i, j), dfs(u) etc.
• User defined structs / classes like Point, Node.
• Even complicated nested datatypes like: map<string, vector<pair<char, unordered_set<long long>>>> WHATTT; etc.

Coloured version of this template is also supported. (Terminal Only)

You can use it on your computer when doing coding challenges on sites like CodeForces.
Additionally, you can use it in online coding environments like LeetCode for practicing data structures and algorithms.

Let's say you have different datatypes such as:

char Char = 'A';
int arr[] = {1, 2, 3, 4};
bitset<8> Bitset(100);
map<string, int> map_String_Int = {{"apple", 5}, {"banana", 3}, {"orange", 7}};

You can debug them like this debug(var1, var2, var3, var4, ...);

debug(Char, arr, Bitset, map_String_Int);

// Output
21: [Char = 'A' || arr = {1,2,3,4} || Bitset = 01100100 || map_String_Int = {("apple",5),("banana",3),("orange",7)}]

If you have user defined structs / classes, you just need to make a print() function, and use debug(...) like you do :)

void print(Point ob) { cerr << "(" << ob.x << "," << ob.y << ")"; }

In instances where array have decayed into pointer, or you declared array at runtime, use debugArr(arr, n);

Note:

• You don't need to remove debug(var, ...) statements in your code when submitting it.
  
• On platforms like Codeforces, there's a macro called ONLINE_JUDGE that's defined, automatically disregarding all your debug statements. This ensures your solution will be accepted unless there's a logical error.

• Copy this template into your own templates. The output will be directed to the stderr stream.
• Alternatively you can make a separate header file and include this into your template.

  #ifndef ONLINE_JUDGE
  #include "template.cpp"
  #else
  #define debug(...)
  #define debugArr(...)
  #endif

• When using it for LeetCode uncomment #define cerr cout and before submitting change #ifndef to #ifdef to ignore debug(...);. For convenience, after changing it, copy it, and keep it pinned in your clipboard for repetitive use.

For Complete Beginners who need step by step tutorial (using VS Code), follow these steps: