[HDU 6447][YJJ's Salesman][2018CCPC网络选拔赛 1010][离散化+线段树+DP]

  1 #include<bits/stdc++.h>
  2 #define rep(i,a,b) for (int i=a;i<=b;i++)
  3 using namespace std;
  4 
  5 const int MAXN=(int)1e5+10;
  6 
  7 struct Point{
  8   int x,y,w;
  9 } p[MAXN];
 10 int posHash[MAXN];
 11 void initHash(int n);
 12 
 13 struct Node{
 14   int l,r,val;
 15 } tree[MAXN*4];
 16 void build(int id,int l,int r);
 17 void update(int id,int pos,int w);
 18 int query(int id,int L,int R);
 19 
 20 int main()
 21 {
 22   int T;
 23   cin>>T;
 24   while (T--) {
 25     int n;
 26     scanf("%d",&n);
 27     rep(i,0,n-1) {
 28     scanf("%d%d%d",&p[i].x,&p[i].y,&p[i].w);
 29     }
 30 
 31     initHash(n);
 32     build(1,1,n);
 33 
 34     int sum=0;
 35     rep(i,0,n-1) {
 36       int temp=p[i].w;
 37       if (p[i].y!=1) {
 38         temp+=query(1,1,p[i].y-1);
 39       }
 40       update(1,p[i].y,temp);
 41       sum=max(sum,temp);
 42     }
 43 
 44     printf("%d\n",sum);
 45   }
 46   return 0;
 47 }
 48 
 49 void initHash(int n)
 50 {
 51   sort(p,p+n,[](const Point &a,const Point &b)
 52              {return a.x<b.x;});
 53   posHash[0]=1;
 54   rep(i,1,n-1) {
 55     if (p[i].x==p[i-1].x) {
 56       posHash[i]=posHash[i-1];
 57     } else {
 58       posHash[i]=posHash[i-1]+1;
 59     }
 60   }
 61   rep(i,0,n-1) {
 62     p[i].x=posHash[i];
 63   }
 64 
 65   sort(p,p+n,[](const Point &a,const Point &b)
 66              {return a.y<b.y;});
 67   posHash[0]=1;
 68   rep(i,1,n-1) {
 69     if (p[i].y==p[i-1].y) {
 70       posHash[i]=posHash[i-1];
 71     } else {
 72       posHash[i]=posHash[i-1]+1;
 73     }
 74   }
 75   rep(i,0,n-1) {
 76     p[i].y=posHash[i];
 77   }
 78 
 79   sort(p,p+n,[](const Point &a,const Point &b)
 80              {return a.x==b.x? a.y>b.y : a.x<b.x;});
 81 }
 82 
 83 void build(int id,int l,int r)
 84 {
 85   tree[id].l=l,tree[id].r=r;
 86   if (l==r) {
 87     tree[id].val=0;
 88     return;
 89   }
 90   int mid=(l+r)/2;
 91   build(id*2,l,mid);
 92   build(id*2+1,mid+1,r);
 93   tree[id].val=max(tree[id*2].val,tree[id*2+1].val);
 94 }
 95 
 96 void update(int id,int pos,int w)
 97 {
 98   int l=tree[id].l,r=tree[id].r;
 99   if (l==r && r==pos) {
100     tree[id].val=max(tree[id].val,w);
101     return;
102   }
103   int mid=(l+r)/2;
104   if (pos<=mid) {
105     update(id*2,pos,w);
106   } else {
107     update(id*2+1,pos,w);
108   }
109   tree[id].val=max(tree[id*2].val,tree[id*2+1].val);
110 }
111 
112 int query(int id,int L,int R)
113 {
114   int l=tree[id].l,r=tree[id].r;
115   if (L<=l && r<=R) {
116     return tree[id].val;
117   }
118   int mid=(l+r)/2;
119   if (R<=mid) {
120     return query(id*2,L,R);
121   } else if (mid<L) {
122     return query(id*2+1,L,R);
123   } else {
124     return max(query(id*2,L,mid),query(id*2+1,mid+1,R));
125   }
126 }