Finish one problem

Codeforces Round 977 (Div. 2, based on COMPFEST 16 - Final Round)/C2. Adjust The Presentation (Hard Version).cpp

@@ -1,4 +1,4 @@
-/* Problem URL: https://codeforces.com/problemset/problem/2021/C2 */
+/* Problem URL: https://codeforces.com/contest/2021/problem/C2 */
 
 #include <bits/stdc++.h>
 #include <ext/pb_ds/assoc_container.hpp>
@@ -91,104 +91,75 @@ void solve()
     int n, m, q;
     cin >> n >> m >> q;
 
-    vi a(n);
-    cin >> a;
-
     vi var(n);
-    V<set<int>> ap(n);
+    V<set<int>> p(n);
     rep(i, n) {
-        var[a[i] - 1] = i;
-        ap[i].insert(oo);
+        int x;
+        cin >> x;
+        var[x - 1] = i;
+        p[i].insert(oo);
     }
 
     vi b(m);
     rep(i, m) {
         cin >> b[i];
-        ap[var[b[i] - 1]].insert(i);
+        b[i]--;
+        p[var[b[i]]].insert(i);
     }
 
-    int sz = n;
-    while (__builtin_popcount(sz) != 1) {
-        sz++;
+    vi df(n - 1);
+    int c = 0;
+    rep(i, n - 1) {
+        df[i] = *p[i + 1].begin() - *p[i].begin();
+        c += df[i] < 0;
     }
 
-    V<ordered_set<pair<int, int>>> seg(sz * 2);
-    vl sum(sz * 2);
-    nrep(i, sz, sz * 2) {
-        seg[i].insert({oo, i - sz});
-    }
+    string ans[] = {
+        "TIDAK",
+        "YA"
+    };
 
-    for (int i = sz - 1; i > 0; i--) {
-        repv(j, seg[i * 2]) {
-            seg[i].insert(j);
+    cout << ans[c == 0] << '\n';
+
+    auto rem = [&](int i) {
+        if (i < n - 1 && df[i] < 0) {
+            c--;
         }
-        repv(j, seg[i * 2 + 1]) {
-            seg[i].insert(j);
-        }
-    }
 
-    auto update = [&](int i, int v) {
-        int ind = i;
-        i += sz;
-        auto bf = *seg[i].begin();
-        seg[i].clear();
-        seg[i].insert({v, i - sz});
-        int now = i & 1;
-        int dd = 0;
-
-        for (i >>= 1; i > 0; i >>= 1) {
-            seg[i].erase(bf);
-            seg[i].insert({v, ind});
-            sum[i] += dd;
-
-            if (now) {
-                int s = seg[i * 2].size() - seg[i * 2].order_of_key({v, oo});
-                int s2 = seg[i * 2].size() - seg[i * 2].order_of_key({bf.first, oo});
-                sum[i] -= s2;
-                sum[i] += s;
-                dd -= s2;
-                dd += s;
-            } else {
-                int s = seg[i * 2 + 1].order_of_key({v, -1});
-                int s2 = seg[i * 2 + 1].order_of_key({bf.first, -1});
-                sum[i] -= s2;
-                sum[i] += s;
-                dd -= s2;
-                dd += s;
-            }
-
-            now = i & 1;
+        if (i > 0 && df[i - 1] < 0) {
+            c--;
         }
     };
 
-    rep(i, n) {
-        update(i, *ap[i].begin());
-    }
+    auto add = [&](int i) {
+        if (i < n - 1) {
+            df[i] = *p[i + 1].begin() - *p[i].begin();
+            c += df[i] < 0;
+        }
 
-    auto check = [&]() {
-        string ans[] = {
-            "TIDAK",
-            "YA"
-        };
-        cout << ans[sum[1] == 0] << '\n';
+        if (i > 0) {
+            df[i - 1] = *p[i].begin() - *p[i - 1].begin();
+            c += df[i - 1] < 0;
+        }
     };
 
-    check();
     while (q--) {
         int i, j;
         cin >> i >> j;
-        i--;
+        i--, j--;
 
         int bf = b[i];
         b[i] = j;
-        int actbf = var[bf - 1];
-        int actb = var[b[i] - 1];
+        j = var[j];
+        bf = var[bf];
+        rem(bf);
+        p[bf].erase(i);
+        add(bf);
+        rem(j);
+        p[j].insert(i);
+        add(j);
 
-        ap[actbf].erase(i);
-        ap[actb].insert(i);
-        update(actbf, *ap[actbf].begin());
-        update(actb, *ap[actb].begin());
-        check();
+        cout << ans[c == 0] << '\n';
     }
 }
 

TODO.md

@@ -147,7 +147,7 @@ Official divs from codeforces
 		I honestly have no idea how to solve this, the editorial didn't help much, I'll get
 		back at it after learning NTT or something.
 	
-	- [ ] [C2. Adjust The Presentation (Hard Version)](https://codeforces.com/problemset/problem/2021/C2)
+	- [X] [C2. Adjust The Presentation (Hard Version)](https://codeforces.com/problemset/problem/2021/C2)
 
 		I already have the idea figured out, but my solution ended up getting TLE, I'll have to come
 		with something better.