P6122 [NEERC2016]Mole Tunnels

https://www.luogu.com.cn/record/99781499

Luogu/P6122/P6122.cpp

@@ -0,0 +1,96 @@
+#include <iostream>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+const int N = 1e5 + 5;
+const int INF = 0x3f3f3f3f;
+
+int n, m, c[N], p[N], f[N << 1], g[N << 1], f2[N], ans;
+
+void update(int u) {
+    f[u] = INF;
+
+    if (c[u]) {
+        f[u] = 0;
+        g[u] = u;
+    }
+
+    if (f[u] > f[u << 1] + (f2[u << 1] < 0 ? -1 : 1)) {
+        f[u] = f[u << 1] + (f2[u << 1] < 0 ? -1 : 1);
+        g[u] = g[u << 1];
+    }
+
+    if (f[u] > f[u << 1 | 1] + (f2[u << 1 | 1] < 0 ? -1 : 1)) {
+        f[u] = f[u << 1 | 1] + (f2[u << 1 | 1] < 0 ? -1 : 1);
+        g[u] = g[u << 1 | 1];
+    }
+}
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    std::fill(std::begin(f), std::end(f), INF);
+
+    cin >> n >> m;
+
+    for (int i = 1; i <= n; i++) {
+        cin >> c[i];
+    }
+
+    for (int i = 1; i <= m; i++) {
+        cin >> p[i];
+    }
+
+    for (int i = n; i; i--) {
+        update(i);
+    }
+
+    for (int i = 1; i <= m; i++) {
+        int x = INF,
+            y = 0,
+            u = p[i],
+            t = 0,
+            v = 0;
+
+        while (u) {
+            if (x > f[u] + t) {
+                x = f[u] + t;
+                y = g[u];
+                v = u;
+            }
+
+            t += (f2[u] > 0 ? -1 : 1);
+            u >>= 1;
+        }
+
+        u = p[i];
+        ans += x;
+
+        while (u != v) {
+            f2[u]--;
+            update(u >>= 1);
+        }
+
+        c[y]--;
+        update(y);
+
+        while (y != v) {
+            f2[y]++;
+            update(y >>= 1);
+        }
+
+        while (v) {
+            update(v);
+            v >>= 1;
+        }
+
+        cout << ans << ' ';
+    }
+
+    cout << endl;
+
+    return 0;
+}