LeetCode 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
.
思路分析:还是考察DP,定义数组sum[i]保存从A[0]到A[i]的最大sum,则sum[i] = Math.max(sum[i⑴], sum[i⑴] + A[i])
AC Code
public class Solution {
public int maxSubArray(int[] A) {
if(A.length == 0) return 0;
if(A.length == 1) return A[0];
int [] sum = new int [A.length];
//sum[i] store the max sum from A[0] to A[i]
sum[0] = A[0];
for(int i = 1; i < A.length; i++){
sum[i] = Math.max(sum[i⑴], sum[i⑴] + A[i]);
}
int maxSum = sum[0];
for(int i = 0; i < A.length; i++){
if(sum[i] > maxSum){
maxSum = sum[i];
}
}
return maxSum;
}
}