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.
一个非常巧的解法:
int maxSubArray(vector<int>& nums) {
int res=nums[0],sum=0;
for(int i=0;i<nums.size();i++){
sum+=nums[i];
res=max(res,sum);
sum=max(sum,0);
}
return res;
}
也可以用动态规划来做:
int maxSubArray(vector<int>& nums) {
if(nums.size()==1)
return nums[0];
vector<int>dp(nums.size());
dp[0]=nums[0];
int res=nums[0];
for(int i=1;i<nums.size();i++){
dp[i]=nums[i]+(dp[i-1]>0?dp[i-1]:0);
res=max(dp[i],res);
}
return res;
}