求最大累加矩阵大小

Posted 2020-09-14 起个po名真费劲

public static int maxMatrixSum(int[][] array) {
int max = 0;
int[] sumArray = null;
int sumArrayLength = array[0].length;
//前两个for作用 第一行到第五行 第二行到第五行 。。。。。 从上到下累加成一维数组
for (int i = 0; i < array.length; i++) {
sumArray = new int[sumArrayLength];
for (int j = i; j < array.length; j++) {
int cur = 0;
//开始变成子数组中最大累加和问题 每一个这个问题需要一个全新的cur
for (int k = 0; k < sumArrayLength; k++) {
cur = cur < 0 ? 0 : cur;
sumArray[k] += array[j][k];
cur += sumArray[k];
max = Math.max(cur, max);
}
}
}
return max;
}

public static void main(String[] args) {
int[][] a = new int[3][5];
for(int i = 0;i < a.length;i ++){
a[i][0] = 3;
a[i][1] = -4;
a[i][2] = 7;
a[i][3] = -4;
a[i][4] = 2;
}
for(int i = 0;i< a.length;i++){
for (int j = 0;j < a[0].length;j ++){
System.out.print(a[i][j] + " ");
}
System.out.println();
}
System.out.println(maxMatrixSum(a));
}