python/TangDou/AcWing_TiGao/T3/MiniPathExtend/1134_Dijkstra.cpp

#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> PII;
const int N = 100010, M = 400010;
const int MOD = 100003;

int n, m;
int cnt[N];
int dis[N];
bool st[N];
int h[N], e[M], ne[M], idx;
void add(int a, int b) {
    e[idx] = b, ne[idx] = h[a], h[a] = idx++;
}

void dijkstra() {
    memset(dis, 0x3f, sizeof dis);
    dis[1] = 0;
    cnt[1] = 1; // 出发点到自己的最短路径有1条，长度是0

    // 小顶堆q
    priority_queue<PII, vector<PII>, greater<PII>> q;
    q.push({0, 1});

    while (q.size()) {
        auto t = q.top();
        q.pop();
        int u = t.second;

        if (st[u]) continue;
        st[u] = true;

        for (int i = h[u]; ~i; i = ne[i]) {
            int j = e[i];
            if (dis[j] > dis[u] + 1) {
                dis[j] = dis[u] + 1;
                cnt[j] = cnt[u];
                q.push({dis[j], j});
            } else if (dis[j] == dis[u] + 1)
                cnt[j] = (cnt[j] + cnt[u]) % MOD;
        }
    }
}

int main() {
    scanf("%d %d", &n, &m);
    memset(h, -1, sizeof h);
    while (m--) {
        int a, b;
        scanf("%d %d", &a, &b);
        add(a, b), add(b, a);
    }
    dijkstra();
    for (int i = 1; i <= n; i++) printf("%d\n", cnt[i]);
    return 0;
}