dijkstra算法–邻接矩阵

#include<iostream>
#include<cstring>
using namespace std;
typedef pair<int, int> PII;
const int N = 2510;
int g[N][N], d[N];
bool s[N];
int main()
{
    int n, m, t1, t2;
    cin >> n >> m >> t1 >> t2;
    memset(g, 0x3f, sizeof(g));
    memset(d, 0x3f, sizeof(d));
    for(int i = 1; i <= m; i++)
    {
        int a, b, c;
        cin >> a >> b >> c;
        g[a][b] = c;
        g[b][a] = c;
    }
    d[t1] = 0;
    for(int i = 0; i < n; i++)
    {
        int t = -1;
        for(int j = 1; j <= n; j++)
        {
            if(!s[j] && (t == -1 || d[t] > d[j])) t = j;
        }
        s[t] = true;
        for(int j = 1; j <= n; j++)
        {
            d[j] = min(d[j], d[t] + g[t][j]);
        }

    }

    cout << d[t2] << endl;

    return 0;
}

dijkstra算法–邻接表

#include<iostream>
#include<cstring>
#include<queue>
using namespace std;
typedef pair<int, int> PII;
const int N = 6210 * 2;
int h[N], ne[N], e[N], w[N], d[N], idx = 0;
bool s[N];
// struct cmp{
//     bool operator()(const PII a, const PII b)
//     {
//         return a.first < b.first; 
//     }
// };

priority_queue<PII, vector<PII>, greater<PII> > p;

void add(int a, int b, int c)
{
    e[idx] = b; w[idx] = c; 
    ne[idx] = h[a]; h[a] = idx++;
}

int main()
{
    int n, m, t1, t2;
    memset(h, -1, sizeof(h));
    cin >> n >> m >> t1 >> t2;
    while(m--)
    {
        int a, b, c;
        cin >> a >> b >> c;
        add(a, b, c);
        add(b, a, c);
    }

    memset(d, 0x3f, sizeof(d));

    d[t1] = 0;
    PII x;
    x.first = 0;
    x.second = t1;

    p.push(x);

    while(p.size())
    {
        int dist = p.top().first;
        int ver = p.top().second;
        p.pop();

        if(s[ver]) continue;
        s[ver] = true;

        for(int i = h[ver]; i != -1; i = ne[i])
        {
            int j = e[i];

            if(d[j] > dist + w[i])
            {
                d[j] = dist + w[i];
                p.push({d[j], j});
            }
        }
    }

    cout << d[t2] << endl;

    return 0;
}