Bzoj 1097 POI2007 Tourist Attractions ATR spfa+ pressure DP

Topic: Given a graph, requires starting from the first point, according to a topological sequence of all the nodes of the 2~k+1, and then reach N, the shortest path

First, the shortest circuit between all the key points is SPFA and the pressure DP

F[STATE][P] Indicates that the point set that has been traversed is state and will go to the shortest point of P

Just a memory search--

Standard cards are over--

#include <cstdio> #include <cstring> #include <iostream> #include <algorithm> #define M 20200using namespace std;struct abcd{int to,f,next;} Table[200200<<1];int head[m],tot;int n,m,k;int map[30][30],topology_map[23];int f[1<<21][23];void Add (    int X,int Y,int z) {table[++tot].to=y;    Table[tot].f=z;    TABLE[TOT].NEXT=HEAD[X]; Head[x]=tot;}    void SPFA (int s) {static int q[65540],f[m];    static unsigned short r,h;    static bool V[m];    int i;    Memset (f,0x3f,sizeof f);    q[++r]=s;f[s]=0;        while (r!=h) {int x=q[++h];v[x]=0; for (I=head[x];i;i=table[i].next) if (F[TABLE[I].TO]&GT;F[X]+TABLE[I].F) {f[table[i].t                O]=F[X]+TABLE[I].F;            if (!v[table[i].to]) v[table[i].to]=1,q[++r]=table[i].to; }} for (i=1;i<=k+1;i++) map[i][s<=k+1?s:k+2]=f[i];}    int STATE_COMPRESSED_DP (int state,int p) {if (F[state][p]) return f[state][p]; IF (!state) return 0;    int i;    f[state][p]=0x3f3f3f3f; for (i=1;i<=k+1;i++) if (state& (1<<i-1) && (topology_map[i]&state) ==0) f[state]    [P]=min (F[STATE][P],STATE_COMPRESSED_DP (state^ (1<<i-1), i) +map[i][p]); return f[state][p];}    int main () {//freopen ("atr11b.in", "R", stdin);    int i,x,y,z,temp;    cin>>n>>m>>k;        for (i=1;i<=m;i++) {scanf ("%d%d%d", &x,&y,&z); ADD (x, y, z);    ADD (Y,X,Z);    } cin>>temp;        for (i=1;i<=temp;i++) {scanf ("%d%d", &x,&y);    topology_map[x]|=1<<y-1;    } for (i=2;i<=k+1;i++) topology_map[1]|=1<<i-1; for (i=1;i<=k+1;i++) SPFA (i);    SPFA (n);    COUT&LT;&LT;STATE_COMPRESSED_DP ((1<<k+1) -1,k+2) <<endl; return 0;}

Bzoj 1097 POI2007 Tourist Attractions ATR spfa+ pressure DP