P1144 最短路计数

R53741486

Luogu/problem/P1144/P1144.cpp

@@ -0,0 +1,41 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+const int mod = 100003;
+
+int n, m, x, y, depth[1000005], cnt[1000005];
+vector<int> g[1000005];
+bool vis[1000005];
+
+int main() {
+    cin >> n >> m;
+    for (int i = 1; i <= m; i++) {
+        cin >> x >> y;
+        g[x].push_back(y);
+        g[y].push_back(x);
+    }
+    queue<int> q;
+    depth[1] = 0;
+    cnt[1] = 1;
+    q.push(1);
+    vis[1] = true;
+    while (!q.empty()) {
+        int t = q.front();
+        q.pop();
+        for (int i : g[t]) {
+            if (!vis[i]) {
+                vis[i] = true;
+                depth[i] = depth[t] + 1;
+                q.push(i);
+            }
+            if (depth[i] == depth[t] + 1) {
+                cnt[i] = (cnt[i] + cnt[t]) % mod;
+            }
+        }
+    }
+    for (int i = 1; i <= n; i++) {
+        cout << cnt[i] % mod << endl;
+    }
+    return 0;
+}