NOIP2015普及组 推销员

洛谷-NOIP2015-推销员

啊这道题自己写的怪怪的……127行啊……而且最后速度也不是很快……

解法：线段树（最近学这个所以就用这个做了）

别看代码……很怪的……

#include<cstdio>
#define MAXN 100005
using namespace std;

const int INF = (int)((long long)(2<<30) - 1);
struct Segment_tree{
    long long max,dis;
    int num,tag;
}Seg[MAXN<<2]; 

long long dis[MAXN];

int N;

inline int read(){
    char ch=getchar();
    int num=0,f=1;
    while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
    while(ch>='0'&&ch<='9')num=num*10+ch-48,ch=getchar();
    return num*f; 
}
inline void write(long long x){
    if(x>9)write(x/10);
    putchar(x%10+'0'); 
}
inline void PushUp(int rt){
    if(Seg[rt<<1].max+Seg[rt<<1].dis>Seg[rt<<1|1].max+Seg[rt<<1|1].dis){
        Seg[rt].max = Seg[rt<<1].max;
        Seg[rt].dis = Seg[rt<<1].dis;
        Seg[rt].num = Seg[rt<<1].num;
    }
    else{
        Seg[rt].max = Seg[rt<<1|1].max;
        Seg[rt].dis = Seg[rt<<1|1].dis;
        Seg[rt].num = Seg[rt<<1|1].num;
    }
}
inline void Build(int l,int r,int rt){
    
    if(l==r){
        Seg[rt].max=(long long)read();
        Seg[rt].dis=dis[l];
        Seg[rt].num=l;
        Seg[rt].tag=0; 
        return;
    }
    int m = (l+r)>>1;
    Build(l,m,rt<<1);
    Build(m+1,r,rt<<1|1);
    PushUp(rt); 
}
inline void Pushdown(int sizel,int sizer,int rt){
    int add = Seg[rt].tag;Seg[rt].tag = 0;
    int l = rt<<1;int r = rt<<1|1;
    Seg[l].tag+=add;Seg[r].tag+=add;
    Seg[l].dis+=(long long)sizel*add;
    Seg[r].dis+=(long long)sizer*add;
    if(Seg[l].dis<0)Seg[l].dis=0;if(Seg[r].dis<0)Seg[r].dis=0;
}
inline void ReBuild(int L,int R,int l,int r,int rt){
    
    if(L>r||l>R)return;
    if(l==r){
        Seg[rt].dis=0;
        return;
    }
    int m = (l+r)>>1;
    Pushdown((m-l+1),(r-m),rt);
    if(L<=m)ReBuild(L,R,l,m,rt<<1);
    if(R>m)ReBuild(L,R,m+1,r,rt<<1|1);
    PushUp(rt);
}

inline void Update(int L,int R,int C,int l,int r,int rt){
    
    if(L>r||l>R)return;
    if(L<=l&&R>=r){
        Seg[rt].dis+=C;
        if(Seg[rt].dis<0)Seg[rt].dis=0;
        Seg[rt].tag+=C;
        return;
    }
    int m = (l+r)>>1;
    Pushdown((m-l+1),(r-m),rt);
    
    if(L<=m)Update(L,R,C,l,m,rt<<1);
    if(R>m)Update(L,R,C,m+1,r,rt<<1|1);
    
    PushUp(rt);
}
inline void Single(int P,int l,int r,int rt){
    if(l==r){
        Seg[rt].max=0;
        Seg[rt].dis=0;
        return;
    }
    int m = (l+r)>>1;
    Pushdown((m-l+1),(r-m),rt);
    
    if(P<=m)Single(P,l,m,rt<<1);
    else Single(P,m+1,r,rt<<1|1);
    
    PushUp(rt);
}
int main(){

    N=read();
    for(register int i=1;i<=N;i++){
        dis[i]=(long long)(read())<<1;
    }
    
    Build(1,N,1);
    
    long long ans = 0;
    int last = -INF;
    int Nul =  1;
    
    for(register int i=1;i<=N;i++){
        
        ans += Seg[1].max+Seg[1].dis;
        write(ans);putchar('\n');
        if(i==N)return 0;
        
        int ago = Seg[1].num;
        if(dis[ago]>last){
            last = dis[ago];
            if(ago-1>=Nul)ReBuild(Nul,ago-1,1,N,1),Nul=ago;
            if(ago+1<=N)Update(ago+1,N,-last,1,N,1);
        }
        
        Single(ago,1,N,1);	
    }
    return 0;
}