【LeetCode从0单刷】Maximum Subarray
【LeetCode从零单刷】Maximum Subarray
题目：
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.
解答：
简单的动态规划。判断以前所有的努力是否对 当前元素 有正影响。
- if (dp[i-1] + nums[i] > dp[i]) dp[i] = dp[i-1] + nums[i];
- else dp[i] = nums[i];
- 找到 dp 中的最大值。
class Solution {
public:
int maxSubArray(vector<int>& nums) {
if(nums.size() == 1){
return nums[0];
}
int* dp = new int[nums.size()];
dp[0] = nums[0];
int max = dp[0];
for(int i = 1; i < nums.size(); i++)
{
if(dp[i-1] + nums[i] > nums[i])
{
dp[i] = dp[i-1] + nums[i];
if(max < dp[i]) max = dp[i];
}
else
{
dp[i] = nums[i];
if(max < dp[i]) max = dp[i];
}
}
return max;
}
};