最短路 vector不T

//A vector不T
// 最短路    SPFA 
//  in数组

#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<queue>
#include<stack>
#include<vector>
#include<deque>
#include<map>
#include<iostream>
using namespace std;
typedef long long  LL;
const double pi=acos(-1.0);
const double e=exp(1);
//const int MAXN =2e5+10;
const int N =332748118;


struct edge
{
    LL to,w;
}two[100009];

LL head[700009];
LL dis[200009];
LL in[200009];
LL check[200009];

vector<struct con > con[700009];
queue<LL > qq;
LL n;

void init()
{
    LL i,p,j;

    memset(head,-1,sizeof(head));
    memset(check,0,sizeof(check));
    for(i = 2; i <= n; i++)
    {
        dis[i] = 9999999999;
    }

}

void BFS()
{
    LL i,p,j;
    LL x;


    qq.push(1);
    check[1] = 1;
    dis[1] = 0;

    while(!qq.empty())
    {
        x = qq.front();
        check[x] = 0;
        qq.pop();

        for(i = 0; i < con[x].size(); i++)
        {
            to = con[x][i].to;
            w = con[x][i].w;
            if(dis[to] > dis[x] + w)
            {
                dis[to] = dis[x] + w;
                in[to] = 1;

                if(check[to] == 0)
                {
                    check[to] = 1;
                    qq.push(to);
                }
            }
            else if(dis[to] == dis[x] + w)
            {
                in[to] ++;
            }
        }
/*
        for(i = head[x]; i != -1; i = edge[i].next)
        {

          //  cout << "x: " << x << "to: " << edge[i].to << endl;
            if(dis[edge[i].to] > dis[x] + edge[i].w)
            {
                dis[edge[i].to] = dis[x] + edge[i].w;
                in[edge[i].to] = 1;
                if(check[edge[i].to] == 0)  //没入队
                {
                    check[ edge[i].to ] = 1;
                    qq.push( edge[i].to );
                }
            }
            else if(dis[edge[i].to] == dis[x] + edge[i].w)
            {
                in[edge[i].to]++;
            }

        }
*/
    }
//
//    for(i = 1; i <= n; i++)
//    {
//        cout << i << ": " << dis[i] << endl;
//    }
}

int main()
{
    LL i,p,j,t;
    LL m,k;
    LL a,b,c,cnt = 0;
    struct edge mid;
    scanf("%lld%lld%lld",&n,&m,&k);

    init();

    while(m--)
    {
        scanf("%lld%lld%lld",&a,&b,&c);

        mid.to = b;
        mid.w = c;
        con[a].push_up(mid);

        mid.to = a;
        con[b].push_up(mid);
/*
        edge[cnt].w = c;
        edge[cnt].to = b;
        edge[cnt].next = head[a];
        head[a] = cnt++;

        edge[cnt].w = c;
        edge[cnt].to = a;
        edge[cnt].next = head[b];
        head[b] = cnt++;
*/
    }

    for(i = 0; i < k; i++)
    {
        scanf("%lld%lld",&b,&c);

        two[i].to = b;
        two[i].w = c;

        mid.to =  b;
        mid.w = c;
        con[1].push_up(mid);
/*
        edge[cnt].w =  c;
        edge[cnt].to = b;
        edge[cnt].next = head[1];
        head[1] = cnt++;
*/
    }

    BFS();
    LL ans = 0;
    for(i = 0; i < k; i++)
    {
        if(dis[ two[i].to ] < two[i].w)
        {
            ans ++;
        }
        else if(dis[ two[i].to ] == two[i].w && in[ two[i].to ] > 1)
        {
            ans++;
            in[ two[i].to ]--;
        }
       // cout << "i: " << con[i].to << " dis: " << dis[ con[i].to ] << " in: " << in[ con[i].to ] << endl;
    }
    printf("%lld
",ans);
    return 0;

}