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// 606. Construct String from Binary Tree
#include "leetcode.h"
/*
* given the root of a binary tree, construct a string consisting of parenthesis
* and integers from a binary tree with the preorder traversal way, and return
* it. omit all the empty parenthesis pairs that do not affect the one-to-one
* mapping relationship between the string and the original binary tree
*/
struct TreeNode {
int val;
struct TreeNode *left;
struct TreeNode *right;
};
void helper(struct TreeNode *t, char *ans, int *count) {
if (!t)
return;
*count += sprintf(&ans[*count], "%d", t->val);
if (!(t->left) && !(t->right))
return;
else {
*count += sprintf(&ans[*count], "(");
helper(t->left, ans, count);
*count += sprintf(&ans[*count], ")");
if (t->right != NULL) {
*count += sprintf(&ans[*count], "(");
helper(t->right, ans, count);
*count += sprintf(&ans[*count], ")");
}
return;
}
}
char *tree2str(struct TreeNode *t) {
char *ans = calloc(30000, sizeof(char));
int count = 0;
helper(t, ans, &count);
ans[count] = '\0';
return ans;
}
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