leetcode53~Maximum Subarray

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.

For example, given the array [-2,1,-3,4,-1,2,1,-5,4],

the contiguous subarray [4,-1,2,1] has the largest sum = 6.

public class MaximumSubarray {

//数组中每个数要么加入到别的组要么以自己作为开头
public int maxSubArray2(int[] nums) {
//记录每一轮最大值
int[] sum = new int[nums.length];
int max;
max = nums[0];
sum[0] = nums[0];

for(int i=1;i<nums.length;i++){
sum[i] = Math.max(nums[i],nums[i]+sum[i-1]);
max = Math.max(max, sum[i]);
}
return max;
}

//可以不使用数组记录 直接用一个常量
public int maxSubArray(int[] nums) {
//记录每一轮最大值
int sum;
int max;
max = nums[0];
sum = nums[0];

for(int i=1;i<nums.length;i++){
sum = Math.max(nums[i],nums[i]+sum);
max = Math.max(max, sum);
}
return max;
}
}