HDU 6619 Horse 斜率优化dp
http://acm.hdu.edu.cn/showproblem.php?pid=6619
#include<bits/stdc++.h> #define fi first #define se second #define INF 0x3f3f3f3f #define LNF 0x3f3f3f3f3f3f3f3f #define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0) #define pqueue priority_queue #define NEW(a,b) memset(a,b,sizeof(a)) const double pi=4.0*atan(1.0); const double e=exp(1.0); const int maxn=1e4+8; typedef long long LL; typedef unsigned long long ULL; const LL mod=1e9+7; const ULL base=1e7+7; const int maxp=26+5; using namespace std; LL a[maxn],f[maxn]; LL g[maxn],gg[maxn]; LL dp[maxn][58]; LL q[58][maxn]; LL l[58],r[58]; LL gdp(int i,int j,int k) {return dp[j][k]-gg[j]-g[j]*(i-j)+gg[i];} LL gfz(int j,int h,int k) {return dp[j][k]-gg[j]+g[j]*(j)-(dp[h][k]-gg[h]+g[h]*(h));} LL gfm(int j,int h) {return g[j]-g[h];} int main(){ int t; scanf("%d",&t); int n,m,k; while(t--){ scanf("%d%d%d",&n,&k,&m); for(int i=1;i<=n;i++){ scanf("%lld",&a[i]); g[i]=g[i-1]+a[i]; gg[i]=g[i]+gg[i-1]; } for(int i=1;i<=k;i++){ l[i]=r[i]=1; q[i][l[i]]=0; } for(int i=1;i<=n;i++){ for(int j=1;j<=i&&j<=k+1;j++){ while(l[j-1]<r[j-1]&&gfz(q[j-1][l[j-1]+1],q[j-1][l[j-1]],j-1)<=i*gfm(q[j-1][l[j-1]+1],q[j-1][l[j-1]])) l[j-1]++; dp[i][j]=gdp(i,q[j-1][l[j-1]],j-1); while(l[j]<r[j]&&gfz(i,q[j][r[j]],j)*gfm(q[j][r[j]],q[j][r[j]-1])<=gfm(i,q[j][r[j]])*gfz(q[j][r[j]],q[j][r[j]-1],j)) r[j]--; q[j][++r[j]]=i; } } for(int i=1;i<=n;i++){ f[i]=a[i]*(n-i+1); } sort(f+1,f+1+n); LL ans=0; for(int i=n;i>=n-m+1;i--){ ans+=f[i]; } ans-=dp[n][k+1]; printf("%lld\n",ans); } }