Binary Tree Traversal (Depth First Search)
05 Aug, 2021Problem
Practice forward and backward traversal of the binary tree as shown in the figure below.
output
- Pre-traversal output:
1 2 4 5 3 6 7 - Inter-traversal output:
4 2 5 1 6 3 7 - Post-traversal output:
4 5 2 6 7 3 1
Solution
Pre traversal
function solution(n) {
let answer = '';
function DFS(v) {
if (v > 7) return;
answer += v;
DFS(v * 2);
// when this finish then next recursive
DFS(v * 2 + 1);
}
DFS(n);
return answer;
}Inter traversal
function solution(n) {
let answer = '';
function DFS(v) {
if (v > 7) return;
DFS(v * 2);
answer += v;
// when this finish then next recursive
DFS(v * 2 + 1);
}
DFS(n);
return answer;
}Post traversal
function solution(n) {
let answer = '';
function DFS(v) {
if (v > 7) return;
DFS(v * 2);
// when this finish then next recursive
DFS(v * 2 + 1);
answer += v;
}
DFS(n);
return answer;
}