hdu 4258斜率优化 状态转移要仔细考虑

#include<iostream>#include<cstring>#include<algorithm>#include<cstdio>#include<vector>#include<sstream>#include<string>#include<climits>#include<stack>#include<set>#include<bitset>#include<cmath>#include<deque>#include<map>#include<queue>#define iinf 2000000000#define linf 1000000000000000000LL#define dinf 1e200#define eps 1e-5#define all(v) (v).begin(),(v).end()#define sz(x)  x.size()#define pb push_back#define mp make_pair#define lng long long#define sqr(a) ((a)*(a))#define pii pair<int,int>#define pll pair<lng,lng>#define pss pair<string,string>#define pdd pair<double,double>#define X first#define Y second#define pi 3.14159265359#define ff(i,xi,n) for(int i=xi;i<=(int)(n);++i)#define ffd(i,xi,n) for(int i=xi;i>=(int)(n);--i)#define ffl(i,r) for(int i=head[r];i!=-1;i=edge[i].next)#define cc(i,j) memset(i,j,sizeof(i))#define two(x)((lng)1<<(x))#define N 1000002#define M 1000000#define lson l , mid , rt << 1#define rson mid + 1 , r , rt << 1 | 1#define Mod  n#define Pmod(x) (x%Mod+Mod)%Modusing namespace std;typedef vector<int>  vi;typedef vector<string>  vs;typedef unsigned int uint;typedef unsigned lng ulng;template<class T> inline void checkmax(T &x,T y){if(x<y) x=y;}template<class T> inline void checkmin(T &x,T y){if(x>y) x=y;}template<class T> inline T Min(T x,T y){return (x>y?y:x);}template<class T> inline T Max(T x,T y){return (x<y?y:x);}template<class T> T gcd(T a,T  b){return (a%b)==0?b:gcd(b,a%b);}template<class T> T lcm(T a,T b){return a*b/gcd(a,b);}template<class T> T Abs(T a){return a>0?a:(-a);}template<class T> inline T lowbit(T n){return (n^(n-1))&n;}template<class T> inline int countbit(T n){return (n==0)?0:(1+countbit(n&(n-1)));}template<class T> inline bool isPrimeNumber(T n){if(n<=1)return false;for (T i=2;i*i<=n;i++) if (n%i==0) return false;return true;}lng n,dp[N],q[N],f,r,c,a[N];int main(){    while(scanf("%I64d%I64d",&n,&c)==2)    {        if(n==0&&c==0) break;        cc(dp,0);        q[0]=0;        f=0,r=0;        a[0]=0;        ff(i,1,n)        {            scanf("%I64d",a+i);        }        ff(i,1,n){            while(r>f)            {                int k=q[f+1],j=q[f];                if(dp[k]+sqr(a[k+1])-dp[j]-sqr(a[j+1])<=(a[k+1]-a[j+1])*a[i]*2)                ++f;                else                break;            }            dp[i]=dp[q[f]]+c+sqr(a[i]-a[q[f]+1]);               while(r>f)            {                int k=q[r],j=q[r-1];                if((dp[i]-dp[k]+sqr(a[i+1])-sqr(a[k+1]))*(a[k+1]-a[j+1])<=(dp[k]+sqr(a[k+1])-dp[j]-sqr(a[j+1]))*(a[i+1]-a[k+1]))                --r;                else                break;            }            q[++r]=i;        }        printf("%I64d\n",dp[n]);    }    return 0;}