Cod sursă (job #708151)

#include <fstream>
#include <algorithm>
#include <vector>
#include <queue>
#include <stdio.h>
#include <ctype.h>

class InParser {
private:
	FILE *fin;
	char *buff;
	int sp;

	char read_ch() {
		++sp;
		if (sp == 4096) {
			sp = 0;
			fread(buff, 1, 4096, fin);
		}
		return buff[sp];
	}

public:
	InParser(const char* nume) {
		fin = fopen(nume, "r");
		buff = new char[4096]();
		sp = 4095;
	}

	InParser& operator >> (int &n) {
		char c;
		while (!isdigit(c = read_ch()) && c != '-');
		int sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}

	InParser& operator >> (long long &n) {
		char c;
		n = 0;
		while (!isdigit(c = read_ch()) && c != '-');
		long long sgn = 1;
		if (c == '-') {
			n = 0;
			sgn = -1;
		} else {
			n = c - '0';
		}
		while (isdigit(c = read_ch())) {
			n = 10 * n + c - '0';
		}
		n *= sgn;
		return *this;
	}
};

#define ll long long
#define pb push_back
#define pii pair<int, int>
#define x first
#define y second

using namespace std;

InParser in("dragoni2.in");
ofstream out("dragoni2.out");

const int NMAX = 805;
const char nl = '\n';
const int INF = 1e9;

struct dragon{
    int x, type, w;
    bool operator <(const dragon &aux) const{
        return w > aux.w;
    }
};

int q, n, m, dmax = -INF, capacity[NMAX], f[NMAX], dist[NMAX][NMAX];

vector<pii> v[NMAX];
/// x - node, y - weight

priority_queue<dragon> pq;


void dfs(int node){
    f[node] = 1;
    if(capacity[node] > dmax)
        dmax = capacity[node];
    for(auto i: v[node]){
        if(!f[i.x] && i.y <= capacity[1])
            dfs(i.x);
    }
}

void dijkstra(){
    dist[1][1] = 0;
    pq.push({1, 1, 0});
    while(!pq.empty()){
        int cur_node = pq.top().x;
        int cur_type = pq.top().type;
        int cur_weight = pq.top().w;

        pq.pop();

        if(capacity[cur_node] > capacity[cur_type]){
            dist[cur_node][cur_node] = min(dist[cur_node][cur_node], dist[cur_node][cur_type]);
            cur_type = cur_node;
        }

        for(auto neigh: v[cur_node]){
            if(dist[neigh.x][cur_type] > cur_weight + neigh.y && neigh.y <= capacity[cur_type]){
                dist[neigh.x][cur_type] = cur_weight + neigh.y;
                pq.push({neigh.x, cur_type, dist[neigh.x][cur_type]});
            }
        }
    }
}

int main()
{
    in >> q >> n >> m;
    for(int i = 1; i <= n; ++i)
        in >> capacity[i];
    for(int i = 1; i <= m; ++i){
        int a, b, c;
        in >> a >> b >> c;
        v[a].pb({b, c});
        v[b].pb({a, c});
    }
    if(q == 1){
        dfs(1);
        out << dmax << nl;
    }

    else{
        for(int i = 1; i <= n; ++i){
            for(int j = 1; j <= n; ++j){
                dist[i][j] = INF;
            }
        }
        dijkstra();
        dmax = INF;
        for(int i = 1; i <= n; ++i)
            dmax = min(dmax, dist[n][i]);
        out << dmax << nl;
    }
    return 0;
}