blah blah blah

abcconj.cpp

@@ -0,0 +1,26 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<ll, ll>;
+using vi = vector<ll>;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    ll n;
+    cin >> n;
+
+    ll ans = 0;
+    for (ll i = 1; i*i*i<=n; i++) {
+        for(ll j = i; j*j*i <= n; j++) {
+            if (n / (i * j) - j + 1 < 0) continue;
+            ans += n / (i * j) - j + 1;
+        }
+    }
+
+    cout << ans << endl;
+
+    return 0;
+}

arrgame.cpp

@@ -0,0 +1,23 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+
+int main() {
+    ll n;
+    cin >> n;
+
+    vector<ll> a(n + 2);
+    a[0] = a[n + 1] = -1;
+    for (ll i = 1; i <= n; i++) cin >> a[i];
+
+    ll l, r;
+    l = r = 0;
+    while (a[l] < a[l + 1]) l++;
+    reverse(a.begin(), a.end());
+    while (a[r] < a[r + 1]) r++;
+
+    cout << (l % 2 || r % 2 ? "Alice" : "Bob") << endl;
+
+    return 0;
+}

arropp.cpp

@@ -0,0 +1,45 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<ll, ll>;
+using vi = vector<ll>;
+using vpi = vector<pi>;
+using vb = vector<bool>;
+
+#include <ext/pb_ds/assoc_container.hpp>
+
+using namespace __gnu_pbds;
+
+template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
+
+void solve(){
+    ll n;
+    cin>>n;
+
+    vi a(n);
+    for(ll i = 0; i < n; i++) {
+        cin >> a[i];
+    }
+
+    Tree<pi> ac;
+    ll ans = 0;
+    for (ll i = 0; i < n; i++) {
+        ac.insert({a[i], i});
+        ll f = ac.order_of_key({a[i], 0});
+        ll u = i+1-ac.order_of_key({a[i], n});
+        ans += min(f, u);
+    }
+    cout << ans << endl;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    ll t;
+    cin >> t;
+    while (t--) solve();
+
+    return 0;
+}

bakery.cpp

@@ -0,0 +1,71 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<ll, ll>;
+using vi = vector<ll>;
+using vb = vector<bool>;
+
+void solve() {
+    ll n, k;
+    cin >> n >> k;
+
+    vi a(n);
+    ll x = 0;
+    for (ll i = 0; i < n; i++) {
+        cin >> a[i];
+        x ^= a[i];
+    }
+
+    vector<set<ll>> ed(n, set<ll>());
+
+    for (ll i = 0; i < n - 1; i++) {
+        ll u, v;
+        cin >> u >> v;
+        u--, v--;
+
+        ed[u].insert(v);
+        ed[v].insert(u);
+    }
+
+    if (x == 0) {
+        cout << "YES" << endl;
+        return;
+    }
+
+    // root tree and do weird xor dfs
+    vi x_sum(n);
+    ll found = 0;
+    function<pair<ll, bool>(ll, ll)> dfs = [&](ll v, ll p) {
+        ll xo = a[v];
+        bool works = true;
+        for (ll child : ed[v]) {
+            if (child != p) {
+                pi f = dfs(child, v);
+                xo ^= f.first;
+                if(f.second) works = false;
+            }
+        }
+        x_sum[v] = xo;
+        if (works && xo == x) found++;
+        if (!works && xo == 0) found++;
+        return make_pair(xo, xo == x || works == false);
+    };
+
+    dfs(0, -1);
+
+    if (found >= 2 && k > 2) cout << "YES" << endl;                         
+    else cout << "NO" << endl;
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    ll t;
+    cin >> t;
+
+    while (t--) solve();
+
+    return 0;
+}

bandit.cpp

@@ -0,0 +1,49 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<ll, ll>;
+using vi = vector<ll>;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    ll n;
+    cin >> n;
+
+    vector<set<ll>> ed(n, set<ll>({}));
+    for (ll i = 1; i < n; i++) {
+        ll p;
+        cin >> p;
+        p--;
+        ed[p].insert(i);
+    }
+
+    vi a(n);
+    for (ll i = 0; i < n; i++) {
+        cin >> a[i];
+    }
+
+    ll max_ans = 0;
+
+    function<pi(ll)> dfs = [&](ll v) {
+        ll sum = a[v];
+        ll sz = 0;
+        for (ll child : ed[v]) {
+            pi ar = dfs(child);
+            sum += ar.first;
+            sz += ar.second;
+        }
+
+        if (sz == 0) sz = 1;
+        max_ans = max(max_ans, (ll)ceil((double)sum / (double)sz));
+        return make_pair(sum, sz);
+    };
+
+    dfs(0);
+
+    cout << max_ans << endl;
+
+    return 0;
+}

banknotes.cpp

@@ -0,0 +1,54 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+
+void solve() {
+    int n, k;
+    cin >> n >> k;
+
+    vector<int> a(n);
+    for (int i = 0; i < n; i++) {
+        cin >> a[i];
+    }
+
+    // calc cost of each place
+    vector<ll> c(20);
+    int r_mx = 0;
+    int pt = 0;
+    ll cur_k = 0;
+    for (int i = 0; i < 20; i++) {
+        while (true) {
+            if (pt + 1 >= n) break;
+            if (a[pt + 1] > i) {
+                break;
+            }
+            pt++;
+        }
+        r_mx = max(r_mx, a[pt]);
+        c[i] = (ll)pow(10,i - r_mx);
+        cur_k += 9 * c[i];
+    }
+
+    ll ans = 0;
+
+    for (int p = 19; p >= 0; p--) {
+        for (int d = 9; d > 0; d--) {
+            cur_k -= c[p];
+            if (!(cur_k > k)) {
+                cur_k += c[p];
+                ans += (ll)pow(10, p) * d;
+                break;
+            }
+        }
+    }
+
+    cout << ans << endl;
+}
+
+int main() {
+    int t;
+    cin >> t;
+
+    while (t--) solve();
+}

building.cpp

@@ -0,0 +1,34 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<ll, ll>;
+using vi = vector<ll>;
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+
+    int n;
+    cin >> n;
+
+    vector<bool> pos(1001);
+
+    for(int i = 1; i < 400; i++) {
+        for(int j = 1; j < 400; j++) {
+            if (4 * i * j + 3 * i + 3 * j > 1000) continue;
+            pos[4 * i * j + 3 * i + 3 * j] = true;
+        }
+    }
+
+    vi a(n);
+    int ans = 0;
+    for (int i = 0; i < n; i++) {
+        cin >> a[i];
+        if(pos[a[i]]) ans++;
+    }
+
+    cout << n - ans << endl;
+
+    return 0;
+}

divis.cpp

@@ -0,0 +1,31 @@
+#include <bits/stdc++.h>
+using namespace std;
+
+int main() {
+    ios::sync_with_stdio(false);
+    cin.tie(0);
+
+    int t;
+    cin >> t;
+
+    int n;
+    int i;
+    int a;
+    int dv;
+    while(t--) {
+        cin >> n;
+        bool done = false;
+        for(i = 1; i <= n; i++) {
+            cin >> a;
+
+            if(done) continue;
+            for(dv = i + 1; a % dv == 0; dv--) {
+                if(dv < 2) done = true;
+            }
+        }
+
+        cout << (done ? "NO" : "YES") << endl;
+    }
+
+    return 0;
+}

flow.cpp

@@ -0,0 +1,33 @@
+    #include <bits/stdc++.h>
+    using namespace std;
+
+    void solve() {
+        int n, m;
+        cin >> n >> m;
+
+        vector<int> p(n + 1);
+        for(int i = 1; i <= n; i++) {
+            int a;
+            cin >> a;
+
+            p[i] = p[i - 1] + a;
+        }
+
+        int ans = 0;
+
+        for(int i = 0; i < m; i++) {
+            int a, b;
+            cin >> a >> b;
+            if(p[b] - p[a - 1] > 0) ans += p[b] - p[a - 1];
+        }
+
+        cout << ans << endl;
+    }
+
+    int main() {
+        int t;
+        cin >> t;
+        while(t--) solve();
+
+        return 0;
+    }