class Solution {
public int[] twoSum(int[] nums, int target) {
for(int i =0;i<nums.length;i++){
for(int j=i+1;j<nums.length;j++){
if(nums[i]+nums[j]==target){
return new int[]{i,j};
}
}
}
return null;
}
}
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode(int x) { val = x; }
* }
*/
class Solution {
public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
ListNode l3 = new ListNode(0);
ListNode p = l3;
int up = 0;
while(l1!=null||l2!=null||up!=0)
{
int x = (l1!=null)? l1.val : 0;
int y = (l2!=null)? l2.val : 0;
p.next = new ListNode((x+y+up)%10);
up = (x+y+up)/10;
p = p.next;
if(l1!=null)
{
l1 = l1.next;
}
if(l2!=null)
{
l2 = l2.next;
}
}
return l3.next;
}
}
class Solution {
public int lengthOfLongestSubstring(String s) {
int maxSub = 0;
List<Character> list = new ArrayList<>();
for(int i=0;i<s.length();i++){
int j =i;
int sum=0;
while(j<s.length()&&!list.contains(s.charAt(j))){
sum++;
list.add(s.charAt(j++));
}
maxSub = maxSub<sum?sum:maxSub;
list.clear();
}
return maxSub;
}
}
class Solution {
public double findMedianSortedArrays(int[] nums1, int[] nums2) {
int[] nums3 = new int[nums1.length+nums2.length];
int i=0;
for(int x:nums1){
nums3[i]=x;
i++;
}
for(int x:nums2){
nums3[i]=x;
i++;
}
Arrays.sort(nums3);
if(i==0)return i/1.0;
if(i==1)return nums3[0]/1.0;
if(i%2==0)
return (nums3[i/2]+nums3[i/2-1])/2.0;
else return nums3[(i-1)/2]/1.0;
}
}
class Solution {
public double findMedianSortedArrays(int[] nums1, int[] nums2) {
int m = nums1.length;
int n = nums2.length;
int[] mn = new int[m+n];
int i=0,j=0,z=0;
while(i<m&&j<n)
{
if(nums1[i]<=nums2[j])
{
mn[z++]=nums1[i++];
}
else
{
mn[z++]=nums2[j++];
}
}
while(i<m)
{
mn[z++]=nums1[i++];
}
while(j<n)
{
mn[z++]=nums2[j++];
}
if((m+n)%2==1)
return mn[(m+n+1)/2-1];
else
return (mn[(m+n)/2]+mn[(m+n)/2-1])/2.0;
}
}
class Solution {
public String longestPalindrome(String s) {
int start=0,end=0;
for(int i=0;i<s.length();i++)
{
int len1 = compareIndexExpore(s,i,i);
int len2 = compareIndexExpore(s,i,i+1);
int len = Math.max(len1,len2);
if(len>end-start){
start = i-(len-1)/2;
end = i+len/2;
}
}
return s.substring(start,end+1);
}
public int compareIndexExpore(String s,int i,int j){
while(i>=0&&j<s.length()&&s.charAt(i)==s.charAt(j)){
i--;
j++;
}
return j-i-1;
}
}
class Solution {
public String convert(String s, int numRows) {
if(numRows<=1)
{
return s;
}
StringBuffer[] buffer = new StringBuffer[numRows];
for(int m=0;m<buffer.length;m++)
buffer[m]=new StringBuffer();
int index = 0;
int flag = 0;
int change = 0;
for(int i = 0;i<s.length();i++)
{
buffer[index].append(s.charAt(i));
if(flag==0)
{
if(index==numRows-1)
{
flag=1;
change=-1;
}
else
{
change=1;
}
}
if(flag==1)
{
if(index==0)
{
flag=0;
change=1;
}
else
{
change=-1;
}
}
index+=change;
}
StringBuffer combine = new StringBuffer();
for(StringBuffer temp:buffer)
{
combine.append(temp.toString());
}
return combine.toString();
}
}
class Solution {
private static int sum;
public int reverse(int x) {
int result=0,newresult=0;
int tail=0;
while(x!=0)
{
tail = x%10;
newresult = result*10+tail;
if((newresult-tail)/10!=result)
return 0;
result = newresult;
x=x/10;
}
return result;
}
}
class Solution {
public int myAtoi(String str) {
int index=0,sign=1,total=0;
//1
if(str.length()==0)
return 0;
//2
while(str.charAt(index)==' '&&index<str.length())
index++;
//3
if(str.charAt(index)=='+'||str.charAt(index)=='-')
{
sign = str.charAt(index)== '+' ? 1 : -1;
index++;
}
//4
while(index<str.length())
{
int digit = str.charAt(index) - '0';
if(digit<0||digit>9)
break;
if(Integer.MAX_VALUE/10<total||Integer.MAX_VALUE/10==total&&Integer.MAX_VALUE%10<digit)
{
return sign == 1 ? Integer.MAX_VALUE : Integer.MIN_VALUE;
}
total = total*10 + digit;
index++;
}
return total*sign;
}
}
class Solution {
public boolean isPalindrome(int x) {
int sum = 0;
int x_temp = x;
int digit = 0;
while(x > 0)
{
digit = x%10;
sum = sum*10 + digit;
x = x/10;
}
return sum==x_temp ? true:false;
}
}
