给定一个数组,找到具有最大和的子数组的长度。
例子 :
Input : a[] = {1, -2, 1, 1, -2, 1}
Output : Length of the subarray is 2
Explanation: Subarray with consecutive elements
and maximum sum will be {1, 1}. So length is 2
Input : ar[] = { -2, -3, 4, -1, -2, 1, 5, -3 }
Output : Length of the subarray is 5
Explanation: Subarray with consecutive elements
and maximum sum will be {4, -1, -2, 1, 5}.
此问题主要是最大和连续子数组问题的变体。
这个想法是,只要此处结束的总和小于0,就更新起始索引。
C++
// C++ program to print length of the largest
// contiguous array sum
#include
using namespace std;
int maxSubArraySum(int a[], int size)
{
int max_so_far = INT_MIN, max_ending_here = 0,
start =0, end = 0, s=0;
for (int i=0; i< size; i++ )
{
max_ending_here += a[i];
if (max_so_far < max_ending_here)
{
max_so_far = max_ending_here;
start = s;
end = i;
}
if (max_ending_here < 0)
{
max_ending_here = 0;
s = i + 1;
}
}
return (end - start + 1);
}
/*Driver program to test maxSubArraySum*/
int main()
{
int a[] = {-2, -3, 4, -1, -2, 1, 5, -3};
int n = sizeof(a)/sizeof(a[0]);
cout << maxSubArraySum(a, n);
return 0;
}
Java
// Java program to print length of the largest
// contiguous array sum
class GFG {
static int maxSubArraySum(int a[], int size)
{
int max_so_far = Integer.MIN_VALUE,
max_ending_here = 0,start = 0,
end = 0, s = 0;
for (int i = 0; i < size; i++)
{
max_ending_here += a[i];
if (max_so_far < max_ending_here)
{
max_so_far = max_ending_here;
start = s;
end = i;
}
if (max_ending_here < 0)
{
max_ending_here = 0;
s = i + 1;
}
}
return (end - start + 1);
}
// Driver code
public static void main(String[] args)
{
int a[] = { -2, -3, 4, -1, -2, 1, 5, -3 };
int n = a.length;
System.out.println(maxSubArraySum(a, n));
}
}
Python3
# Python3 program to print largest contiguous array sum
from sys import maxsize
# Function to find the maximum contiguous subarray
# and print its starting and end index
def maxSubArraySum(a,size):
max_so_far = -maxsize - 1
max_ending_here = 0
start = 0
end = 0
s = 0
for i in range(0,size):
max_ending_here += a[i]
if max_so_far < max_ending_here:
max_so_far = max_ending_here
start = s
end = i
if max_ending_here < 0:
max_ending_here = 0
s = i+1
return (end - start + 1)
# Driver program to test maxSubArraySum
a = [-2, -3, 4, -1, -2, 1, 5, -3]
print(maxSubArraySum(a,len(a)))
C#
// C# program to print length of the
// largest contiguous array sum
using System;
class GFG {
// Function to find maximum subarray sum
static int maxSubArraySum(int []a, int size)
{
int max_so_far = int.MinValue,
max_ending_here = 0,start = 0,
end = 0, s = 0;
for (int i = 0; i < size; i++)
{
max_ending_here += a[i];
if (max_so_far < max_ending_here)
{
max_so_far = max_ending_here;
start = s;
end = i;
}
if (max_ending_here < 0)
{
max_ending_here = 0;
s = i + 1;
}
}
return (end - start + 1);
}
// Driver code
public static void Main(String[] args)
{
int []a = {-2, -3, 4, -1, -2, 1, 5, -3};
int n = a.Length;
Console.Write(maxSubArraySum(a, n));
}
}
// This code is contributed by parashar...
PHP
= 0)
{
$y++;
$slope_error_new -= 2 * ($x2 - $x1);
}
}
}
// Driver Code
$x1 = 3; $y1 = 2; $x2 = 15; $y2 = 5;
bresenham($x1, $y1, $x2, $y2);
// This code is contributed by nitin mittal.
?>
Javascript
输出 :
5