Recently Irina arrived to one of the most famous cities of Berland — the Berlatov city. There are n showplaces in the city, numbered from1 to n, and some of them are connected by one-directional roads. The roads in Berlatov are designed in a way such that there are nocyclic routes between showplaces.
Initially Irina stands at the showplace 1, and the endpoint of her journey is the showplace n. Naturally, Irina wants to visit as much showplaces as she can during her journey. However, Irina's stay in Berlatov is limited and she can't be there for more than T time units.
Help Irina determine how many showplaces she may visit during her journey from showplace 1 to showplace n within a time not exceedingT. It is guaranteed that there is at least one route from showplace 1 to showplace n such that Irina will spend no more than T time units passing it.
The first line of the input contains three integers n, m and T (2 ≤ n ≤ 5000, 1 ≤ m ≤ 5000, 1 ≤ T ≤ 109) — the number of showplaces, the number of roads between them and the time of Irina's stay in Berlatov respectively.
The next m lines describes roads in Berlatov. i-th of them contains 3 integers ui, vi, ti (1 ≤ ui, vi ≤ n, ui ≠ vi, 1 ≤ ti ≤ 109), meaning that there is a road starting from showplace ui and leading to showplace vi, and Irina spends ti time units to pass it. It is guaranteed that the roads do not form cyclic routes.
It is guaranteed, that there is at most one road between each pair of showplaces.
Print the single integer k (2 ≤ k ≤ n) — the maximum number of showplaces that Irina can visit during her journey from showplace 1 to showplace n within time not exceeding T, in the first line.
Print k distinct integers in the second line — indices of showplaces that Irina will visit on her route, in the order of encountering them.
If there are multiple answers, print any of them.
4 3 13
1 2 5
2 3 7
2 4 8
3
1 2 4
6 6 7
1 2 2
1 3 3
3 6 3
2 4 2
4 6 2
6 5 1
4
1 2 4 6
5 5 6
1 3 3
3 5 3
1 2 2
2 4 3
4 5 2
3
1 3 5
分析：dp+拓扑排序；
dp[i][j]枚举到达i点共经过j个城市的所需最小时间；
对于从1出发可以到达的点进行拓扑排序，然后再依次枚举即可；
代码：
#include <iostream> #include <cstdio> #include <cstdlib> #include <cmath> #include <algorithm> #include <climits> #include <cstring> #include <string> #include <set> #include <map> #include <queue> #include <stack> #include <vector> #include <list> #define rep(i,m,n) for(i=m;i<=n;i++) #define rsp(it,s) for(set<int>::iterator it=s.begin();it!=s.end();it++) #define mod 1000000007 #define inf 0x3f3f3f3f #define vi vector<int> #define pb push_back #define mp make_pair #define fi first #define se second #define ll long long #define pi acos(-1.0) #define pii pair<int,int> #define Lson L, mid, rt<<1 #define Rson mid+1, R, rt<<1|1 const int maxn=5e3+10; using namespace std; ll gcd(ll p,ll q){return q==0?p:gcd(q,p%q);} ll qpow(ll p,ll q){ll f=1;while(q){if(q&1)f=f*p;p=p*p;q>>=1;}return f;} int n,m,k,t,to,h[maxn],tot,dp[maxn][maxn],pre[maxn][maxn],du[maxn],vis[maxn]; struct node { int to,nxt,t; }e[maxn]; void add(int x,int y,int t) { tot++; e[tot].to=y; e[tot].nxt=h[x]; e[tot].t=t; h[x]=tot; } void bfs() { queue<int>p; p.push(1);vis[1]=1; while(!p.empty()) { int q=p.front();p.pop(); for(int i=h[q];i;i=e[i].nxt) { int to=e[i].to; if(vis[to])continue; vis[to]=1; p.push(to); } } for(int i=1;i<=n;i++) for(int j=h[i];j;j=e[j].nxt) { int to=e[j].to; if(vis[i])du[to]++; } } void gao() { queue<int>p; p.push(1); dp[1][1]=0; while(!p.empty()) { int q=p.front();p.pop(); for(int i=h[q];i;i=e[i].nxt) { int to=e[i].to,ti=e[i].t; if(!du[to])continue; for(int j=1;j<=n;j++) { if(dp[to][j]>dp[q][j-1]+ti&&dp[q][j-1]+ti<=t) { dp[to][j]=dp[q][j-1]+ti; pre[to][j]=q; } } if(--du[to]==0)p.push(to); } } } void dfs(int now,int x) { if(now!=1)dfs(pre[now][x],x-1); printf("%d ",now); } int main() { int i,j; memset(dp,inf,sizeof(dp)); scanf("%d%d%d",&n,&m,&t); rep(i,1,m) { int a,b,c; scanf("%d%d%d",&a,&b,&c); add(a,b,c); } bfs(); gao(); for(i=n;i>=2;i--)if(dp[n][i]!=inf){printf("%d ",i);break;} dfs(n,i); //system("Pause"); return 0; }