优化了一下之前写的dijkstra，使这段代码变得更好看()

#include <iostream>
#include <queue>
#include <algorithm>
#include <cstring>
using namespace std;
typedef pair<int, int> pii;
const int N = 2e5 + 10, INF = 0x3f3f3f3f;
int n, m;
int e[N], ne[N], h[N], w[N], d[N], idx;
bool st[N];

void intit() {
    memset(h, -1, sizeof h);
    memset(d, INF, sizeof d);
    d[1] = 0;
}

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

int dijkstra() {
    priority_queue<pii, vector<pii>, greater<>> q;
    q.push({0, 1});
    while (q.size()) {
        pii t = q.top();
        q.pop();
        int p = t.second, dist = t.first;
        if (st[p]) continue;
        st[p] = true;
        for (int i = h[p]; ~i ; i = ne[i]) {
            int j = e[i];
            if (d[j] > dist + w[i]) {
                d[j] = w[i] + dist;
                q.push({d[j], j});
            }
        }
    }

    return d[n] == INF ? -1 : d[n];
}

int main() {

    cin >> n >> m;
    intit();
    while (m--) {
        int a, b, c;
        scanf("%d %d %d", &a, &b, &c);
        add(a, b, c);
    }

    cout << dijkstra() << endl;
}