leetcode/PathSum.java at master · mengli/leetcode · GitHub

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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}
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/**
 * Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up
 * all the values along the path equals the given sum.
 *
 * <p>For example: Given the below binary tree and sum = 22, 5 / \ 4 8 / / \ 11 13 4 / \ \ 7 2 1
 * return true, as there exist a root-to-leaf path 5->4->11->2 which sum is 22.
 */
publicclassPathSum {
publicbooleanhasPathSum(TreeNoderoot, intsum) {
if (root == null) returnfalse;
if (root.left == null && root.right == null && root.val == sum) returntrue;
booleanl = root.left != null ? hasPathSum(root.left, sum - root.val) : false;
booleanr = root.right != null ? hasPathSum(root.right, sum - root.val) : false;
returnl || r;
 }
}