hdu 4258 斜率DP

思路：dp[i]=dp[j]+(num[i]-num[j+1])^2;

#include<iostream>
#include<cstring>
#include<algorithm>
#include<cstdio>
#define Maxn 1000010
#define LL unsigned __int64
using namespace std;
LL dp[Maxn],num[Maxn];
int que[Maxn*];
inline int ReadInt()
{
     char ch = getchar();
     int data = ;
     while (ch < '' || ch > '')
         ch = getchar();
     do
     {
         data = data* + ch-'';
         ch = getchar();
     } while (ch >= '' && ch <= '');
     return data;
 }
int main()
{
    int n,i,j;
    LL c;
    while(scanf("%d%I64u",&n,&c)!=EOF,n||c){
        memset(dp,,sizeof(dp));
        for(i=;i<=n;i++)
            num[i]=(LL)ReadInt();
        int head,rear;
        head=;rear=;
        que[++rear]=;
        dp[]=;
        for(i=;i<=n;i++){
            while(head<rear&&(dp[que[head+]]+num[que[head+]+]*num[que[head+]+]-(dp[que[head]]+num[que[head]+]*num[que[head]+])<=*num[i]*(num[que[head+]+]-num[que[head]+])))
                head++;
            dp[i]=dp[que[head]]+(num[i]-num[que[head]+])*(num[i]-num[que[head]+])+c;
            while(head<rear&&(dp[i]+num[i+]*num[i+]-(dp[que[rear]]+num[que[rear]+]*num[que[rear]+]))*(num[que[rear]+]-num[que[rear-]+])<=(dp[que[rear]]+num[que[rear]+]*num[que[rear]+]-(dp[que[rear-]]+num[que[rear-]+]*num[que[rear-]+]))*(num[i+]-num[que[rear]+]))
                rear--;
            que[++rear]=i;
        }
        printf("%I64u\n",dp[n]);
    }
    return ;
}