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.
解题思路
动态规划思想
以nums数组[-2,1,-3,4,-1]为例
- dp[0]为-2
- dp[1] = max(dp[0]+nums[1],1)=max(-2,1)=1
- dp[2] = max(dp[1]+nums[2],-3)=max(1-3,-3)=-2
- 当前的sum为dp[i-1]+nums[i], nums[i]最大值
- 然后将maxSum和sum进行比较，取最大值
Go代码实现
Go代码实现1
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func (a int, b int)int {
if a>b {
return a
}else{
return b
}
}
func maxSubArray(nums []int) int {
n := len(nums)
if n == 0 {
return 0
}
if n == 1 {
return nums[0]
大专栏 L53-Maximum-Subarrays="line"> }
sums := make([]int, n)
maxSum := nums[0]
sums[0] = nums[0]
for i:=1;i<n ; i++ {
sums[i] = max(sums[i-1]+nums[i], nums[i])
maxSum = max(sums[i], maxSum)
}
return maxSum
}
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Go代码实现2
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| func maxSubArray(nums []int) int {
n := len(nums)
if n == 0 {
return 0
}
maxSum := nums[0]
curSum := nums[0]
for i:=1;i<n ; i++ {
if curSum<0 {
curSum = nums[i]
}else{
curSum += nums[i]
}
if curSum>maxSum {
maxSum = curSum
}
}
return maxSum
}
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参考文档