【DP】【单调队列】17.6.3 上网 题解

Normal: f[i]=max{f[i-1],f[x-1]+c[x,i]} f[0]=0
c[x,i]表示x玩到i的快乐值
Rare: 加单调队列优化

#include<cstdio>#include<cstdlib>#include<algorithm>using namespace std;#define N 500100#define M 300000struct node{int x,y,c;} e[M];int n,T,tot,tree[N];inline void read(int &x){    x=0; char ch; while(ch=getchar(),ch>'9' || ch<'0');    while(ch>='0' && ch<='9') x=x*10+ch-'0',ch=getchar();}inline int Max(int x,int y){return x>y?x:y;}inline bool cmp(node A,node B){ return A.y<B.y; }inline void insert(int x,int y){    for(;x<=T;x+=x&-x) tree[x]=Max(tree[x],y);}inline int Query(int x){    int ret=0;    for(;x;x-=x&-x) ret=Max(ret,tree[x]);    return ret;}int main(){    freopen("net.in","r",stdin);    freopen("net.out","w",stdout);    read(n); read(T);    for(int i=1,m;i<=n;i++)    {        read(m);        for(;m--;) {            ++tot;            read(e[tot].x);            read(e[tot].y);            read(e[tot].c);        }    }    sort(e+1,e+1+tot,cmp);    for(int i=1,tmp;i<=tot;i++)    {        tmp=Query(e[i].x-1)+e[i].c;        if(tmp>Query(e[i].y))        insert(e[i].y,tmp);    }    printf("%d\n",Query(T));    return 0;}