最大连续子序列
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner scanner= new Scanner(System.in);
String str = scanner.nextLine();
String [] arr = str.split(" ");
int [] array = new int[arr.length];
for (int i = 0; i < arr.length; i++) {
array[i] = Integer.parseInt(arr[i]);
}
System.out.println(findGreatestSumOfSubArray(array));
}
public static int findGreatestSumOfSubArray(int[] array) {
if(array.length==0)
return 0;
else{
int total=array[0],maxSum=array[0];
for(int i=1;i<array.length;i++){
if(total>=0)
total+=array[i];
else
total=array[i];
if(total>maxSum)
maxSum=total;
}
return maxSum;
}
}
}
无序数组找到第K大的数
import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
String[] ss = in.nextLine().split(" ");
int[] array = new int[ss.length];
for(int i =0;i<ss.length;i++) {
array[i]=Integer.parseInt(ss[i]);
}
int K = in.nextInt();
System.out.println( findKthLargest(array,K));
}
public static int findKthLargest(int[] nums, int k) {
if (k < 1 || nums == null) {
return 0;
}
return getKth(nums.length - k + 1, nums, 0, nums.length - 1);
}
public static int getKth(int k, int[] nums, int start, int end) {
int pivot = nums[end];
int left = start;
int right = end;
while (true) {
while (nums[left] < pivot && left < right) {
left++;
}
while (nums[right] >= pivot && right > left) {
right--;
}
if (left == right) {
break;
}
swap(nums, left, right);
}
swap(nums, left, end);
if (k == left + 1) {
return pivot;
} else if (k < left + 1) {
return getKth(k, nums, start, left - 1);
} else {
return getKth(k, nums, left + 1, end);
}
}
public static void swap(int[] nums, int n1, int n2) {
int tmp = nums[n1];
nums[n1] = nums[n2];
nums[n2] = tmp;
}
}
这个是有漏洞的，没考虑到重复数字的情况