Add solution to 'a lot' of problems

Easy/minimum-depth-of-binary-tree/solution.cpp

@@ -0,0 +1,38 @@
+#include <cstdint>
+#include <iostream>
+
+struct TreeNode {
+    int val;
+    TreeNode *left;
+    TreeNode *right;
+    TreeNode() : val(0), left(nullptr), right(nullptr) {}
+    TreeNode(int x) : val(x), left(nullptr), right(nullptr) {}
+    TreeNode(int x, TreeNode *left, TreeNode *right) : val(x), left(left), right(right) {}
+};
+
+class Solution {
+public:
+    void traverse(TreeNode *root, int curlvl, int &minCount) {
+        if (root == nullptr) {
+            return;
+        }
+
+        if (root->left == nullptr && root->right == nullptr && curlvl < minCount) {
+            minCount = curlvl;
+        }
+
+        traverse(root->left, curlvl + 1, minCount);
+        traverse(root->right, curlvl + 1, minCount);
+    }
+
+    int minDepth(TreeNode *root) {
+        if (root == nullptr) {
+            return 0;
+        }
+
+        int minCount = INT32_MAX;
+        traverse(root, 1, minCount);
+
+        return minCount;
+    }
+};