# Deepest Leaves Sum in C++

C++Server Side ProgrammingProgramming

Suppose we have a binary tree, we have to find the sum of values of its deepest leaves. So if the tree is like − Then the output will be 15.

To solve this, we will follow these steps −

• Define a map m, and maxDepth
• Define a recursive method solve(), this will take node and level, initially level is 0
• if node is not present, then return
• maxDepth := max of level and maxDepth
• increase m[level] by value of node
• solve(left of node, level + 1)
• solve(right of node, level + 1)
• In the main method, setup maxDepth := 0, then solve(root, 0)
• return m[maxDepth]

## Example

Let us see the following implementation to get better understanding −

class Solution {
public:
int maxDepth;
map <int, int> m;
void solve(TreeNode* node, int level = 0){
if(!node)return;
maxDepth = max(level, maxDepth);
m[level] += node->val;
solve(node->left, level + 1);
solve(node->right, level + 1);
}
int deepestLeavesSum(TreeNode* root) {
maxDepth = 0;
m.clear();
solve(root);
//cout << maxDepth << endl;
return m[maxDepth];
}
};

## Input

[1,2,3,4,5,null,6,7,null,null,null,null,8]

## Output

15