Commit04c8b79

committed

[java][105] Add solution without using Array.copyOfRange()

1 parent884b3b9 commit04c8b79Copy full SHA for 04c8b79

File tree

+30

-0

lines changed

+30

-0

lines changed

Lines changed: 30 additions & 0 deletions

Original file line number	Diff line number	Diff line change
`@@ -29,3 +29,33 @@ public TreeNode buildTree(int[] preorder, int[] inorder) {`
`29`	`29`	`returnroot;`
`30`	`30`	`}`
`31`	`31`	`}`
	`32`	`+`
	`33`	`+// Solution without using Array copies`
	`34`	`+classSolution {`
	`35`	`+`
	`36`	`+Map<Integer,Integer>inorderPositions =newHashMap<>();`
	`37`	`+`
	`38`	`+publicTreeNodebuildTree(int[]preorder,int[]inorder) {`
	`39`	`+if(preorder.length <1 \|\|inorder.length <1)returnnull;`
	`40`	`+`
	`41`	`+for(inti =0;i <inorder.length;i ++) {`
	`42`	`+inorderPositions.put(inorder[i],i);`
	`43`	`+ }`
	`44`	`+`
	`45`	`+returnbuilder(preorder,0,0,inorder.length-1);`
	`46`	`+ }`
	`47`	`+`
	`48`	`+publicTreeNodebuilder(int[]preorder,intpreorderIndex,intinorderLow,intinorderHigh) {`
	`49`	`+if (preorderIndex >preorder.length-1 \|\|inorderLow >inorderHigh)returnnull;`
	`50`	`+`
	`51`	`+intcurrentVal =preorder[preorderIndex];`
	`52`	`+TreeNoden =newTreeNode(currentVal);`
	`53`	`+intmid =inorderPositions.get(currentVal);`
	`54`	`+`
	`55`	`+n.left =builder(preorder,preorderIndex+1,inorderLow,mid-1);`
	`56`	`+n.right =builder(preorder,preorderIndex + (mid -inorderLow) +1,mid+1,inorderHigh);`
	`57`	`+`
	`58`	`+returnn;`
	`59`	`+ }`
	`60`	`+`
	`61`	`+}`

Comments

(0)