add LeetCode 108

Author: ytlm

c/LeetCode/108.convert-sorted-array-to-binary-search-tree.c

@@ -0,0 +1,106 @@
+struct TreeNode* createNode() {
+
+    struct TreeNode* temp;
+
+    temp = (struct TreeNode*)malloc(sizeof(struct TreeNode));
+
+    if (temp == NULL) {
+        return NULL;
+    }
+
+    temp->left = NULL;
+    temp->right = NULL;
+
+    return temp;
+}
+
+void csabst(struct TreeNode** root, int* nums, int l, int r) {
+
+    if (l >= r) {
+        return;
+    }
+
+    struct TreeNode* node;
+
+    int sum, med, index;
+
+    node = createNode();
+    if(node == NULL) {
+        return ;
+    }
+
+    sum = (r - l);
+
+    med = sum / 2;
+
+    index = l + med;
+
+    // printf("l:%d, r:%d, sum:%d, med:%d, index:%d, val:%d\n", l, r, sum, med, index, nums[index]);
+
+    node->val = nums[index];
+
+    *root = node;
+
+    csabst(&(node->left), nums, l, index);
+    csabst(&(node->right), nums, index + 1, r);
+
+}
+
+struct TreeNode* sortedArrayToBST(int* nums, int numsSize){
+
+    if (numsSize < 1 ) {
+        return NULL;
+    }
+
+    struct TreeNode* root;
+
+    csabst(&root, nums, 0, numsSize);
+
+    return root;
+}
+
+/*
+void printNode(struct TreeNode *node) {
+    if (node == NULL) {
+        return;
+    }
+    printf("%d\t", node->val);
+
+    printNode(node->left);
+    printNode(node->right);
+}
+
+void freeNode(struct TreeNode *node) {
+    if (node == NULL) {
+        return;
+    }
+
+    freeNode(node->left);
+    freeNode(node->right);
+
+    free(node);
+
+    node = NULL;
+}
+
+int main(int argc, char *argv[])
+{
+    int nums[10];
+
+    nums[0] = -10;
+    nums[1] = -3;
+    nums[2] = 0;
+    nums[3] = 5;
+    nums[4] = 9;
+
+    struct TreeNode *root = sortedArrayToBST(nums, 0);
+
+    printf("--------------------\n");
+    printNode(root);
+    printf("\n--------------------\n");
+
+    freeNode(root);
+
+    return 0;
+}
+*/