Uva 1754 Posterize

#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<=b;++i)
#define ms(arr,a) memset(arr,a,sizeof arr)
/*
2 1
50 20000
150 10000
*/
typedef long long ll;
const int maxn=260;
int r[maxn];
ll p[maxn],sump[maxn],sumpr[maxn],sumprr[maxn];
ll dp[maxn][maxn];

ll getval(int l,int r)
{
    double a,b,c;
    a=sump[r]-sump[l-1];
    b=-2*(sumpr[r]-sumpr[l-1]);
    c=sumprr[r]-sumprr[l-1];
    ll x1,x3;
    double x2=-b/2./a;
    x1=floor(x2),x3=ceil(x2);
    return min(a*x1*x1+b*x1+c,a*x3*x3+b*x3+c);
}
int main()
{
    int d,k;
    while(~scanf("%d%d",&d,&k))
    {
        ms(dp,0x3f);
        dp[0][0]=0;
        rep(i,1,d)
        {
            scanf("%d%d",r+i,p+i);
            sump[i]=sump[i-1]+p[i];
            sumpr[i]=sumpr[i-1]+p[i]*r[i];
            sumprr[i]=sumprr[i-1]+p[i]*r[i]*r[i];
        }
        rep(j,1,k)
        {
            rep(i,1,d)
            {
                rep(k,j,i)
                {
                    dp[i][j]=min(dp[i][j],getval(k,i)+dp[k-1][j-1]);
                }
            }
        }
        printf("%lld\n",dp[d][k]);
    }
}