CPP

kadane algorithm

public int kadane(int[] arr){
	int max_so_far = 0, curr_max = Integer.MIN_VALUE;
    for(int i: arr){
    	max_so_far += i;
        if(max_so_far<0) max_so_far = 0;
        if(max_so_far>curr_max) curr_max = max_so_far;
    }
    return curr_max;
}

kadane algorithm

Lets take the example:
    {-2, -3, 4, -1, -2, 1, 5, -3}

    max_so_far = max_ending_here = 0

    for i=0,  a[0] =  -2
    max_ending_here = max_ending_here + (-2)
    Set max_ending_here = 0 because max_ending_here < 0

    for i=1,  a[1] =  -3
    max_ending_here = max_ending_here + (-3)
    Set max_ending_here = 0 because max_ending_here < 0

    for i=2,  a[2] =  4
    max_ending_here = max_ending_here + (4)
    max_ending_here = 4
    max_so_far is updated to 4 because max_ending_here greater 
    than max_so_far which was 0 till now

    for i=3,  a[3] =  -1
    max_ending_here = max_ending_here + (-1)
    max_ending_here = 3

    for i=4,  a[4] =  -2
    max_ending_here = max_ending_here + (-2)
    max_ending_here = 1

    for i=5,  a[5] =  1
    max_ending_here = max_ending_here + (1)
    max_ending_here = 2

    for i=6,  a[6] =  5
    max_ending_here = max_ending_here + (5)
    max_ending_here = 7
    max_so_far is updated to 7 because max_ending_here is 
    greater than max_so_far

    for i=7,  a[7] =  -3
    max_ending_here = max_ending_here + (-3)
    max_ending_here = 4

kadane algo

class Solution {
public:
    int maxSubArray(vector<int>& nums) {
        int curMax = 0, maxTillNow = INT_MIN;
        for(auto c : nums)
            curMax = max(c, curMax + c),
            maxTillNow = max(maxTillNow, curMax);
        return maxTillNow;
    }
};