HDU-3001 travelling (state compression)

A person wants to travel, he wants to go all over the city, but the same city does not want to stroll more than 2 times. Now given the traffic tolls between cities, he can choose any point as the starting point. What is the minimum fare for all the cities?

Problem solving: This problem is similar to POJ-3311 Hie with the pie
The status mark here is represented by a three-digit number, which indicates the number of times each city has been gone.
Set Dp[i][state] for the current city in I, stroll the city state for the minimum toll
State transition equation:
Dp[i][s + I city mark] = min (dp[i][s + i city Mark], Dp[j][s] + cost[j][i])
Pay attention to the side of the sentence
I used the queue again ...

#include <cstdio>#include <cstring>#include <algorithm>#include <queue>using namespace STD;#define MAXN#define INF 0x3f3f3f3f#define MAXS 60000structDP {intnum, State;} START[MAXN];intN, M;intCOST[MAXN][MAXN];intDP[MAXN][MAXS];intMOD[MAXN];voidInit () {intX, y, Z;memset(Cost,0x3f,sizeof(cost)); for(inti =0; I < m; i++) {scanf("%d%d%d", &x, &y, &z); cost[x-1][y-1] = cost[y-1][x-1] = min (cost[x-1][y-1], z); }memset(DP,0x3f,sizeof(DP)); for(inti =0; I < n; i++) {Dp[i][mod[i]] =0;        Start[i].num = i;    Start[i].state = Mod[i]; }}voidSolve () { queue<DP>Q for(inti =0; I < n; i++) Q.push (Start[i]);intans = INF; while(!q.empty ())        {DP T = Q.front (); Q.pop (); for(inti =0; I < n; i++) {if(i = = T.num | | cost[i][t.num] = = INF)Continue;if(!i && t.state%3==2)Continue;if(I && (t.state% mod[i+1])-(t.state% mod[i]))/mod[i] = =2)Continue;if(Dp[i][t.state + mod[i]] > Dp[t.num][t.state] + cost[t.num][i])                {dp[i][t.state + mod[i]] = Dp[t.num][t.state] + cost[t.num][i];                DP tt;                Tt.num = i;                Tt.state = T.state + mod[i]; Q.push (TT);BOOLFlag =false;intTMP = T.state + mod[i];if(Dp[i][tmp] < ans) { for(intj =0; J < N; J + +)if(tmp%3==0) {flag =true; Break; }Else{tmp/=3; }if(!flag) ans = dp[i][t.state + mod[i]]; }            }        }    }if(ans = = INF) ans =-1;printf("%d\n", ans);}voidBegin () {mod[0] =1; for(inti =1; I < A; i++) Mod[i] = mod[i-1] *3;}intMain () {begin (); while(scanf("%d%d", &n, &m)! = EOF) {init ();    Solve (); }return 0;}

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HDU-3001 travelling (state compression)