Maximum Subarray

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.

注解：查找最大连续子串

解：遍历数组，记录当前位置之前的最大连续子串和，若nums[i]加入到连续子串尾的和小于nums[i],则当前最大子串为以nums[i]开头的子串

int maxSubArray(vector<int>& nums) {    int n = nums.size();    if( n == 0 )        return 0;        int res = nums[0], sum = nums[0];        for( int i = 1; i < n; ++i )    {        sum += nums[i];        if( nums[i] >= sum )            sum = nums[i];                if( sum > res )            res = sum;    }    return res;}