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.
click to show more practice.
More practice:
If you have figured out the O(n) solution, try coding another solution using the divide and conquer approach, which is more subtle.
方法一:
class Solution {
public:
int maxSubArray(vector<int>& nums) {
// int p = 0;
int q = 0;
int max = nums[0];
int val = nums[0];
while( q < nums.size() - 1 ){
q++;
if( val < 0 )
val = nums[q];
else
val += nums[q];
if( max < val )
max = val;
}
return max;
}
};
方法二:
class Solution {
public:
int maxSubArray(vector<int>& nums) {
int ls = nums[0];
int val = 0;
for(int i = 0; i < nums.size(); i++){
val += nums[i];
ls = max( val , ls );
val = max( val , 0 );
}
return ls;
}
};