ural 1090. In the Army Now

#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

const int N = 10007;

int c
, n;

int lowbit(int i) 
{
    return i&(-i);
}

void add(int i, int val) 
{
    while(i <= n) 
    {
        c[i] += val;
        i += lowbit(i);
    }
}

int sum(int i) 
{
    int s = 0;
    while(i > 0) 
    {
        s += c[i];
        i -= lowbit(i);
    }
    return s;
}

int main() 
{
    int k, s, max, i, j, x, max_f;
    while(~scanf("%d%d", &n, &k))
    {
        max = 0; max_f = 1;
        for(i = 0; i < k; i++) 
        {
            memset(c, 0, sizeof(c));
            for(s = 0, j = 0; j < n; j++)
            {
                scanf("%d", &x);
                x = n - x + 1;
                add(x, 1);
                s += sum(x-1);
            }
            if(s > max)    {max = s; max_f = i+1;}
        }
        cout << max_f << endl;
    }
    return 0;
}