1 #include<cstdio>
 2 int n,f=1,r,top=1,tai=1,ans=888888888,c[20010],w[20010],d[20010],s[20010];
 3 int  all(int a,int b){return c[b]-c[a]-w[a-1]*(d[b]-d[a]); }
 4 double k(int a,int b){return (double)(w[a]*d[a]-w[b]*d[b])/(double)(w[a]-w[b]);}
 5 int main(){
 6     scanf("%d",&n);    s[1]=1;
 7     for (int i=1; i<=n  ; i++) scanf("%d%d",&w[i],&d[i+1]);
 8     for (int i=2; i<=n+1; i++) w[i] += w[i-1];
 9     for (int i=2; i<=n+1; i++) c[i]  = c[i-1]+w[i-1]*d[i] ;
10     for (int i=2; i<=n+1; i++) d[i] += d[i-1];
11     for (int i=2; i<=n; i++){
12         while (top< tai&&k(s[top],s[top+1])<=  d[ i ]   ) top++;
13         while (top<=tai&&k(s[tai-1],s[tai])>=k(s[tai],i)) tai--;
14         r = c[ s[top] ] + all(s[top]+1,i) + all(i+1,n+1);
15         if (r<ans) ans=r; s[++tai]=i;
16     }   printf("%d",ans);
17 }

 1 #include<cstdio>
 2 long long top=0,tai=0,s[50010],f[50010],n,l,K,h[50010];
 3 long double k(int a,int b) {
 4     return (long double)(f[b]+h[b]*h[b]-f[a]-h[a]*h[a])
 5           /(long double)(h[b]-h[a]);
 6 }
 7 int main(){
 8     scanf("%lld%lld",&n,&l);
 9     for (int i=1; i<=n; i++) scanf("%lld",&h[i]);
10     for (int i=1; i<=n; i++) h[i]+=h[i-1]+1;
11     for (int i=1; i<=n; i++) {
12         K=h[i]-1-l;
13         while (top< tai&&k(s[top],s[top+1])<=2*K) top++;
14         f[i]=f[s[top]]+(K-h[s[top]])*(K-h[s[top]]);
15         while (top<=tai&&k(s[tai-1],s[tai])>=k(s[tai],i)) tai--;
16         s[++tai]=i;
17     }   printf("%lld",f[n]);
18 }

 1 #include<cstdio>
 2 #include<algorithm>
 3 struct p{long long a,b;}t[50010];
 4 long long l,n,top=0,tai=0,f[50010],s[50010];
 5 bool cmp(const p&x,const p&y) {return (x.a<y.a)||(x.a==y.a&&x.b<y.b);}
 6 long double k(long long j1,long long j2 )  {
 7     return (long double)(f[j1]-f[j2])/
 8            (long double)(t[j2+1].b-t[j1+1].b);
 9 }
10 int main(){
11     scanf("%lld",&n);
12     for (int i=1; i<=n; i++) scanf("%lld%lld",&t[i].a,&t[i].b);
13     std::sort(t+1,t+n+1,cmp);
14     for (int i=1; i<=n; i++) {
15         while (l&&t[i].b>=t[l].b) l--;
16         t[++l].a=t[i].a;
17         t[  l].b=t[i].b;
18     }
19     for (int i=1; i<=l; i++) {
20         while (top< tai&&k(s[top],s[top+1])<=  t[ i ].a ) top++;
21         f[i]=f[s[top]]+t[i].a*t[s[top]+1].b;
22         while (top<=tai&&k(s[tai-1],s[tai])>=k(s[tai],i)) tai--;
23         s[++tai]=i;
24     }   printf("%lld",f[l]);
25 }