153 lines
3.2 KiB
C++
153 lines
3.2 KiB
C++
#include<cstdio>
|
|
#include<vector>
|
|
#include<set>
|
|
#include<queue>
|
|
#include<algorithm>
|
|
#define mp make_pair
|
|
#define pb push_back
|
|
#define fi first
|
|
#define sc second
|
|
using namespace std;
|
|
const int N = 201010;
|
|
const int M = 2010101;
|
|
const int inf = 2100000000;
|
|
typedef pair<int,int> P;
|
|
priority_queue<P,vector<P>,greater<P> > Q;
|
|
int n,m,i,a,b,c,dis[N],cnt[N],dis1[N],cnt1[N],dis2[N],cnt2[N],X;
|
|
int id[N],ID[N],Id[N];
|
|
vector<P> e[N];
|
|
void gao(int x)
|
|
{
|
|
int i;
|
|
for (i=1;i<=n;i++)
|
|
dis[i]=inf,cnt[i]=0;
|
|
dis[x]=0;
|
|
cnt[x]=1;
|
|
Q.push(mp(0,x));
|
|
while (!Q.empty())
|
|
{
|
|
P tmp=Q.top();
|
|
Q.pop();
|
|
x=tmp.sc;
|
|
if (dis[x]!=tmp.fi) continue;
|
|
for (i=0;i<e[x].size();i++)
|
|
if (dis[x]+e[x][i].sc<dis[e[x][i].fi])
|
|
{
|
|
dis[e[x][i].fi]=dis[x]+e[x][i].sc;
|
|
cnt[e[x][i].fi]=cnt[x];
|
|
Q.push(mp(dis[e[x][i].fi],e[x][i].fi));
|
|
}
|
|
else
|
|
if (dis[x]+e[x][i].sc==dis[e[x][i].fi])
|
|
{
|
|
cnt[e[x][i].fi]+=cnt[x];
|
|
if (cnt[e[x][i].fi]>X) cnt[e[x][i].fi]=X;
|
|
}
|
|
}
|
|
}
|
|
|
|
int ls[M],rs[M],s[M],tot,root[N];
|
|
void build(int &x,int a,int b)
|
|
{
|
|
x=++tot;
|
|
ls[x]=rs[x]=s[x]=0;
|
|
if (b-a>1)
|
|
{
|
|
int m=(a+b)>>1;
|
|
build(ls[x],a,m);
|
|
build(rs[x],m,b);
|
|
}
|
|
}
|
|
void insert(int y,int &x,int a,int b,int l,int r)
|
|
{
|
|
x=++tot;
|
|
ls[x]=ls[y];rs[x]=rs[y];s[x]=s[y]+1;
|
|
if ((a<=l)&&(r<=b))
|
|
return;
|
|
int m=(l+r)>>1;
|
|
if (a<m) insert(ls[y],ls[x],a,b,l,m);
|
|
if (m<b) insert(rs[y],rs[x],a,b,m,r);
|
|
}
|
|
int query(int x,int a,int b,int l,int r)
|
|
{
|
|
if ((a<=l)&&(r<=b))
|
|
return s[x];
|
|
int m=(l+r)>>1,ans=0;
|
|
if (a<m) ans+=query(ls[x],a,b,l,m);
|
|
if (m<b) ans+=query(rs[x],a,b,m,r);
|
|
return ans;
|
|
}
|
|
bool cmp(int a,int b)
|
|
{
|
|
return dis2[a]<dis2[b];
|
|
}
|
|
bool CMP(int a,int b)
|
|
{
|
|
return cnt2[a]>cnt2[b];
|
|
}
|
|
int main()
|
|
{
|
|
while (~scanf("%d%d",&n,&m))
|
|
{
|
|
if (n+m==0) return 0;
|
|
for (i=1;i<=n;i++) e[i].clear();
|
|
scanf("%d",&X);
|
|
for (i=1;i<=m;i++)
|
|
{
|
|
scanf("%d%d%d",&a,&b,&c);
|
|
e[a].pb(mp(b,c));
|
|
e[b].pb(mp(a,c));
|
|
}
|
|
gao(1);
|
|
for (i=1;i<=n;i++)
|
|
dis1[i]=dis[i],cnt1[i]=cnt[i];
|
|
gao(n);
|
|
for (i=1;i<=n;i++)
|
|
dis2[i]=dis[i],cnt2[i]=cnt[i];
|
|
|
|
tot=0;
|
|
build(root[0],0,n);
|
|
for (i=1;i<=n;i++)
|
|
id[i]=i;
|
|
sort(id+1,id+1+n,cmp);
|
|
for (i=1;i<=n;i++)
|
|
ID[id[i]]=i;
|
|
|
|
for (i=1;i<=n;i++)
|
|
Id[i]=i;
|
|
sort(Id+1,Id+1+n,CMP);
|
|
for (i=1;i<=n;i++)
|
|
insert(root[i-1],root[i],ID[Id[i]]-1,ID[Id[i]],0,n);
|
|
long long ans=0;
|
|
for (i=1;i<=n;i++)
|
|
{
|
|
int l=1,r=n;
|
|
while (l<=r)
|
|
{
|
|
m=(l+r)>>1;
|
|
if (dis2[id[m]]+dis1[i]+1<=dis1[n]) l=m+1;else r=m-1;
|
|
}
|
|
int j=r;
|
|
|
|
l=1;r=n;
|
|
while (l<=r)
|
|
{
|
|
m=(l+r)>>1;
|
|
if (1LL*cnt1[i]*cnt2[Id[m]]>=X) l=m+1;else r=m-1;
|
|
}
|
|
|
|
if (j) ans=ans+query(root[r],0,j,0,n);
|
|
|
|
|
|
for (int k=0;k<e[i].size();k++)
|
|
if (dis2[e[i][k].fi]+1+dis1[i]<=dis1[n])
|
|
if (1LL*cnt1[i]*cnt2[e[i][k].fi]>=X) ans--;
|
|
|
|
if (dis1[i]+dis2[i]+1<=dis1[N])
|
|
if (1LL*cnt1[i]*cnt2[i]>=X) ans--;
|
|
|
|
}
|
|
printf("%lld\n",ans);
|
|
}
|
|
}
|