91 lines
1.6 KiB
C++
91 lines
1.6 KiB
C++
#include <bits/stdc++.h> // {{{
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// https://codeforces.com/blog/entry/96344
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#pragma GCC optimize("O2,unroll-loops")
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#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
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using namespace std;
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using i32 = int32_t;
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using u32 = uint32_t;
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using i64 = int64_t;
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using u64 = uint64_t;
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using d64 = double;
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using d128 = long double;
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template <typename T>
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using vec = std::vector<T>;
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template <typename T, size_t N>
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using arr = std::array<T, N>;
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template <typename T1, typename T2>
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using pai = std::pair<T1, T2>;
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template <typename T>
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constexpr T MIN = std::numeric_limits<T>::min();
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template <typename T>
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constexpr T MAX = std::numeric_limits<T>::max();
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template <typename T>
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[[nodiscard]] static T sc(auto&& x) {
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return static_cast<T>(x);
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}
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template <typename T>
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[[nodiscard]] static T sz(auto&& x) {
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return static_cast<T>(x.size());
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}
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static void NO() {
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std::cout << "NO\n";
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}
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static void YES() {
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std::cout << "YES\n";
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}
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#define all(x) (x).begin(), (x).end()
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#define rall(x) (x).rbegin(), (x).rend()
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#ifdef LOCAL
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#define db(...) std::print(__VA_ARGS__)
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#define dbln(...) std::println(__VA_ARGS__)
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#else
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#define db(...)
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#define dbln(...)
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#endif
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// }}}
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void solve() {
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i64 l, r;
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cin >> l >> r;
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i64 lo = 0, hi = r - l + 1;
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while (lo <= hi) {
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i64 mid = lo + (hi - lo) / 2;
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if (l + mid * (mid + 1) / 2 <= r) {
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lo = mid + 1;
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} else {
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hi = mid - 1;
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}
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}
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// NOTE: hi is # elems ADDING; so also include l implciitly
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cout << hi + 1 << '\n';
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}
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int main() { // {{{
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cin.tie(nullptr)->sync_with_stdio(false);
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cin.exceptions(cin.failbit);
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int tc = 1;
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cin >> tc;
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for (int t = 0; t < tc; ++t) {
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solve();
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}
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return 0;
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}
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// }}}
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