ソースコード
// g++ macro.cpp -std=c++14
#include <bits/stdc++.h>
typedef long long ll;
const int INF = 1e9;
const int MOD = 1e9+7;
const ll LINF = 1e18;
using namespace std;
#define dump(x) cout << #x << " = " << (x) << endl;
#define YES(n) cout << ((n) ? "YES" : "NO" ) << endl
#define Yes(n) cout << ((n) ? "Yes" : "No" ) << endl
#define POSSIBLE(n) cout << ((n) ? "POSSIBLE" : "IMPOSSIBLE" ) << endl
#define Possible(n) cout << ((n) ? "Possible" : "Impossible" ) << endl
#define possible(n) cout << ((n) ? "possible" : "impossible" ) << endl
#define SANKOU(n,a,b) cout << ((n) ? (#a) : (#b) ) << endl
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) for(int i=0;i<(n);++i)
#define REPR(i,n) for(int i=n;i>=0;i--)
#define FOREACH(x,a) for(auto& (x) : (a) )
#define WFA(d,v) REP(k,v)REP(i,v)REP(j,v)d[i][j]=min(d[i][j],d[i][k]+d[k][j])
#define SCOUT(x) cout<<(x)<<" "
#define ENDL cout<<endl
#define VECCIN(x) for(auto&youso_: (x) )cin>>youso_
#define VECIN2(x,y) REP(i,x.size())cin>>x[i]>>y[i]
#define VECCOUT(x) if(1){for(auto tt=x.begin();tt!=x.end();tt++){if(tt!=x.begin())cout<<" ";cout<<(*tt);}cout<<endl;}
#define ALL(obj) (obj).begin(),(obj).end()
#define EXIST(n,x) (find(ALL(n),x)!=n.end())
#define UNIQUE(obj) sort(ALL( obj )); obj.erase(unique(ALL(obj)),obj.end())
#define EN(x) if(1){cout<<#x<<endl;return 0;}
#define COUT(x) cout<<(x)<<endl
void CINT(){}
template <class Head,class... Tail>
void CINT(Head&& head,Tail&&... tail){
cin>>head;
CINT(move(tail)...);
}
#define CIN(...) int __VA_ARGS__;CINT(__VA_ARGS__)
#define LCIN(...) ll __VA_ARGS__;CINT(__VA_ARGS__)
#define SCIN(...) string __VA_ARGS__;CINT(__VA_ARGS__)
template <class T = ll>
T IN(){T x;cin>>x;return (x);}
template <class Head>
void VT(Head head){}
template <class Head,class Seco,class... Tail>
void VT(Head&& head,Seco&& seco,Tail&&... tail){
seco.resize(head);
VT(head,move(tail)...);
}
void VT2(){}
template <class Head,class... Tail>
void VT2(Head&& head,Tail&&... tail){
VECCIN(head);
VT2(move(tail)...);
}
template <class Head>
void VT3(Head&& head){}
template <class Head,class Seco,class... Tail>
void VT3(Head&& head,Seco&& seco,Tail&&... tail){
seco[head]=IN();
VT3(head,move(tail)...);
}
#define VC1(n,...) V __VA_ARGS__;VT(n,__VA_ARGS__);VT2(__VA_ARGS__); //aaabbbccc
#define VC2(n,...) V __VA_ARGS__;VT(n,__VA_ARGS__);REP(i,n)VT3(i,__VA_ARGS__); //abcabcabc
// #include <boost/multiprecision/cpp_int.hpp>
// using namespace boost::multiprecision; // cpp_int
#define P pair<ll,ll>
#define V vector<ll>
#define M map<ll,ll>
#define S set<ll>
#define pb(a) push_back(a)
#define mp make_pair
class Dijkstra{
public:
Dijkstra(vector<vector<P>> ed,ll firs,ll pnum);
void Solve();
V range;// range[a]=b;
vector<vector<P>> edges;// [a][b]=c;
priority_queue<P,vector<P>,greater<P>> que;// queue=(range,poll);
V keiro;
V CalcRoute(ll startp,ll endp);
};
Dijkstra::Dijkstra(vector<vector<P>> ed,ll firs,ll pnum){
edges=ed;
V ttt(pnum,LINF);
range=ttt;
range[firs]=0;
que.push(mp(0,firs));
keiro=V(pnum);
REP(i,pnum)keiro[i]=i;
}
void Dijkstra::Solve(){
while(!que.empty()){
P top_=que.top();
que.pop();
FOREACH(x,edges[top_.second]){
if(range[x.first] > range[top_.second] + x.second){
range[x.first] = range[top_.second] + x.second;
que.push(mp(range[x.first],x.first));
keiro[x.first] = top_.second;
}
}
}
}
V Dijkstra::CalcRoute(ll startp,ll endp){
V vec(1,endp);
ll poll = endp;
while(poll==startp){
poll = keiro[poll];
vec.pb(poll);
}
return vec;
}
int main(){
CIN(n,m,k);
VC2(m,a,b,c);
VC2(k,h,d);
vector<vector<P>> edges(n+1);
REP(i,m){
edges[a[i]].pb(mp(b[i],c[i]));
edges[b[i]].pb(mp(a[i],c[i]));
}
REP(i,k)
edges[n].pb(mp(h[i], 1LL*(1e6 - d[i])));
Dijkstra dijk(move(edges), n, n+1);
dijk.Solve();
int cnt = 0;
REP(i,n)
cnt += dijk.range[i] <= 1e6;
COUT(cnt);
return 0;
}