单源最短路 : 计数

标签：target   cond   long   sync   ace   owb   name   mes   ref   

https://www.acwing.com/problem/content/1136/

#include <bits/stdc++.h>
using namespace std;
#define IO ios::sync_with_stdio(false);cin.tie(0); cout.tie(0)
inline int lowbit(int x) { return x & (-x); }
#define ll long long
#define pb push_back
#define PII pair<int, int>
#define x first
#define y second
#define inf 0x3f3f3f3f
const int N = 1e5 + 7, M = 4e5 + 7, mod = 100003;
int n, m;
int h[N], e[M], ne[M], idx;
int dist[N], cnt[N];
int q[N];

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

int bfs() {
    memset(dist, 0x3f, sizeof dist);
    dist[1] = 0;
    cnt[1] = 1;
    int hh = 0, tt = 0;
    q[0] = 1;
    while (hh <= tt) {
        int t = q[hh++];
        for (int i = h[t]; ~i; i = ne[i]) {
            int j = e[i];
            if (dist[j] > dist[t] + 1) {
                dist[j] = dist[t] + 1;
                cnt[j] = cnt[t];
                q[++tt] = j;
            }
            else if (dist[j] == dist[t] + 1) cnt[j] = (cnt[j] + cnt[t]) % mod;
        }
    }
}

int main() {
    IO;
    cin >> n >> m;
    memset(h, -1, sizeof h);
    while (m--) {
        int a, b;
        cin >> a >> b;
        add(a, b), add(b, a);
    }
    bfs();
    for (int i = 1; i <= n; ++i) cout << cnt[i] << "\n";
    return 0;
}

单源最短路 : 计数

标签：target   cond   long   sync   ace   owb   name   mes   ref   

原文地址：https://www.cnblogs.com/phr2000/p/14396117.html