Topcoder SRM 683 Div2 B

贪心的题，从左向右推过去即可

#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <ctime>

using namespace std;

class MoveStonesEasy {
public:
    int get(vector <int>, vector <int>);
};

int MoveStonesEasy::get(vector <int> a, vector <int> b) 
{
    int sum1 = 0,sum2 = 0;

    for(int i = 0; i < a.size() ; i++)  
    {
        sum1 += a[i];

        sum2 += b[i];   
    }

    if(sum1!=sum2)
    {
        return -1;
    }
    sum1 = 0;
    for(int i = 0; i<a.size();i++)
    {
        if(a[i]<b[i])
        {
            sum1+=(b[i]-a[i]);

            a[i+1] -=(b[i]-a[i]);
        }
        else if(a[i]>b[i])
        {
            sum1+=(a[i]-b[i]);

            a[i+1]+=(a[i]-b[i]);
        }
    }

    return sum1;
}