子数组的最大和

子数组的最大和 

 方法1：

public static int max(int [] a){int max = 0;int b = 0;for (int i=0;i<a.length;i++){if (b<0)b= a[i];elseb+=a[i];if (max<b)max = b;}return max;}

方法2：

public int maxSubsum(int[] a){int[] b = new int[a.length+1];for (int i=0;i<a.length+1;i++)b[i]=0;for (int i=0;i<a.length;i++){for (int j= i;j<a.length;j++)if (b[i+1]<b[i]+a[i])b[i+1]=b[i]+a[i];//b[i]记录 任意j到i的最大和}int max = 0;for (int i=0;i<a.length+1;i++){if (b[i]>max)max = b[i];}//System.out.println(max);// i j max// i  j+1 < max// i-1 j < max return max;}