C

#include <stdio.h>
#include <string.h>

#define MAXSIZE 510
#define INF 0x3f3f3f3f
#define min(a,b) ((a)<(b)?(a):(b))
int n, m, graph[MAXSIZE][MAXSIZE], visited[MAXSIZE], dist[MAXSIZE];

void addEdge(int from, int to, int weight) {
    graph[from][to] = min(graph[from][to], weight);
}

void dijkstra(int start) {
    dist[start] = 0;
    for (int i = 1; i <= n; ++i) {
        int v = -1, curMin = INF;
        for (int j = 1; j <= n; ++j) {
            if (!visited[j] && dist[j] < curMin) {
                v = j;
                curMin = dist[j];
            }
        }

        if (v == -1) {
            return;
        }

        visited[v] = 1;
        for (int u = 1; u <= n; ++u) {
            if (!visited[u] && graph[v][u] != INF && dist[v]+graph[v][u] < dist[u]) {
                dist[u] = dist[v] + graph[v][u];
            }
        }
    }
}

void init() {
    int x, y, z;
    memset(graph, 0x3f, sizeof(graph));
    memset(dist, 0x3f, sizeof(dist));

    scanf("%d%d", &n, &m);
    while (m--) {
        scanf("%d%d%d", &x, &y, &z);
        addEdge(x, y, z);
    }
}

int main() {
    init();
    dijkstra(1);
    if (dist[n] == INF) {
        puts("-1");
    } else {
        printf("%d\n", dist[n]);
    }

    return 0;
}

C++

#include <iostream>
#include <vector>
using namespace std;

const int MAXSIZE = 510;
const int INF = 0x3f3f3f3f;
int n, m;
vector<vector<int> > graph(MAXSIZE, vector<int>(MAXSIZE, INF));
vector<bool> visited(MAXSIZE, false);
vector<int> dist(MAXSIZE, INF);

void addEdge(int from, int to, int weight) {
    graph[from][to] = min(graph[from][to], weight);
}

void dijkstra(int start) {
    dist[start] = 0;
    for (int i = 1; i <= n; ++i) {
        int v = -1, curMin = INF;
        for (int j = 1; j <= n; ++j) {
            if (!visited[j] && dist[j] < curMin) {
                v = j;
                curMin = dist[j];
            }
        }

        if (v == -1) {
            return;
        }

        visited[v] = true;
        for (int u = 1; u <= n; ++u) {
            if (!visited[u] && graph[v][u] != INF && dist[v]+graph[v][u] < dist[u]) {
                dist[u] = dist[v] + graph[v][u];
            }
        }
    }
}

void init() {
    int x, y, z;
    cin >> n >> m;
    while (m--) {
        cin >> x >> y >> z;
        addEdge(x, y, z);
    }
}

int main() {
    init();
    dijkstra(1);
    if (dist[n] == INF) {
        cout << -1 << endl;
    } else {
        cout << dist[n] << endl;
    }

    return 0;
}

Go

package main

import "fmt"

const INF = 0x3f3f3f3f

var (
    n, m    int
    graph   [][]int
    visited []bool
    dist    []int
)

func init() {
    fmt.Scan(&n, &m)
    graph = make([][]int, n+1)
    for i := 0; i < len(graph); i++ {
        graph[i] = make([]int, n+1)
        for j := 0; j < len(graph[i]); j++ {
            graph[i][j] = INF
        }
    }
    visited = make([]bool, n+1)
    dist = make([]int, n+1)
    for i := 0; i < len(dist); i++ {
        dist[i] = INF
    }

    var x, y, z int
    for i := 0; i < m; i++ {
        fmt.Scan(&x, &y, &z)
        addEdge(x, y, z)
    }
}

func minInt(a, b int) int {
    if a < b {
        return a
    }
    return b
}

func addEdge(from, to, weight int) {
    graph[from][to] = minInt(graph[from][to], weight)
}

func dijkstra(start int) {
    dist[start] = 0
    for i := 1; i <= n; i++ {
        v, curMin := -1, INF
        for j := 1; j <= n; j++ {
            if !visited[j] && dist[j] < curMin {
                v = j
                curMin = dist[j]
            }
        }

        if v == -1 {
            return
        }

        visited[v] = true
        for u := 1; u <= n; u++ {
            if !visited[u] && graph[v][u] != INF && dist[v]+graph[v][u] < dist[u] {
                dist[u] = dist[v] + graph[v][u]
            }
        }
    }
}

func main() {
    dijkstra(1)
    if dist[n] == INF {
        fmt.Println(-1)
    } else {
        fmt.Println(dist[n])
    }
}