BZOJ 1835 基站选址(DP+线段树)

 

# include <cstdio>
# include <cstring>
# include <cstdlib>
# include <iostream>
# include <vector>
# include <queue>
# include <stack>
# include <map>
# include <set>
# include <cmath>
# include <algorithm>
using namespace std;
# define lowbit(x) ((x)&(-x))
# define pi acos(-1.0)
# define eps 1e-9
# define MOD 1024523
# define INF 1000000000
# define mem(a,b) memset(a,b,sizeof(a))
# define FOR(i,a,n) for(int i=a; i<=n; ++i)
# define FO(i,a,n) for(int i=a; i<n; ++i)
# define bug puts("H");
# define lch p<<1,l,mid
# define rch p<<1|1,mid+1,r
# define mp make_pair
# define pb push_back
typedef pair<int,int> PII;
typedef vector<int> VI;
# pragma comment(linker, "/STACK:1024000000,1024000000")
typedef long long LL;
int Scan() {
    int x=0,f=1;char ch=getchar();
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
void Out(int a) {
    if(a<0) {putchar('-'); a=-a;}
    if(a>=10) Out(a/10);
    putchar(a%10+'0');
}
const int N=20005;
//Code begin...

int n, k, d[N], c[N], s[N], w[N], bg[N], ed[N], seg[N<<3], tag[N<<3];
VI v[N];
LL dp[N];

void _init(){
    FOR(i,1,n) {
        int l=d[i]-s[i], r=d[i]+s[i];
        l=lower_bound(d+1,d+n+1,l)-d; r=lower_bound(d+1,d+n+1,r)-d;
        if (d[r]>d[i]+s[i]) --r;
        bg[i]=l; ed[i]=r; v[r].pb(i);
    }
}
void push_up(int p){seg[p]=min(seg[p<<1],seg[p<<1|1]);}
void push_down(int p){
    if (!tag[p]) return ;
    seg[p]+=tag[p]; tag[p<<1]+=tag[p]; tag[p<<1|1]+=tag[p]; tag[p]=0;
}
void init(int p, int l, int r){
    if (l<r) {
        int mid=(l+r)>>1;
        tag[p]=0; init(lch); init(rch); push_up(p);
    }
    else seg[p]=dp[l], tag[p]=0;
}
int query(int p, int l, int r, int L, int R){
    push_down(p);
    if (L>r||R<l) return INF;
    if (L<=l&&R>=r) return seg[p];
    int mid=(l+r)>>1;
    return min(query(lch,L,R),query(rch,L,R));
}
void update(int p, int l, int r, int L, int R, int val){
    push_down(p);
    if (L>r||R<l) return ;
    if (L<=l&&R>=r) tag[p]=val, push_down(p);
    else {
        int mid=(l+r)>>1;
        update(lch,L,R,val); update(rch,L,R,val); push_up(p);
    }
}
int main ()
{
    scanf("%d%d",&n,&k);
    FOR(i,2,n) scanf("%d",d+i); FOR(i,1,n) scanf("%d",c+i);
    FOR(i,1,n) scanf("%d",s+i); FOR(i,1,n) scanf("%d",w+i);
    ++n; ++k; d[n]=INF; w[n]=INF;
    _init();
    LL ans, tmp=0;
    FOR(i,1,n) {
        dp[i]=tmp+c[i];
        FO(j,0,v[i].size()) tmp+=w[v[i][j]];
    }
    ans=dp[n];
    FOR(i,2,k) {
        init(1,1,n);
        FOR(j,1,n) {
            dp[j]=(j>1?query(1,1,n,1,j-1):0)+c[j];
            FO(l,0,v[j].size()) if (bg[v[j][l]]>1) update(1,1,n,1,bg[v[j][l]]-1,w[v[j][l]]);
        }
        ans=min(ans,dp[n]);
    }
    printf("%lld\n",ans);
    return 0;
}