add agc47 A

Author: biracubos37

AtCoder/AGC47/A.cpp

@@ -0,0 +1,116 @@
+#include <bits/stdc++.h>
+
+#define int long long
+#define double long double
+#define ff first
+#define ss second
+#define endl '\n'
+#define ii pair<int, int>
+#define mp make_pair
+#define mt make_tuple
+#define DESYNC \
+ ios_base::sync_with_stdio(false); \
+ cin.tie(0); \
+ cout.tie(0)
+#define pb push_back
+#define vi vector<int>
+#define vii vector<ii>
+#define all(x) x.begin(), x.end()
+#define EPS 1e-9
+#define INF 1e18
+#define ROOT 1
+#define M 1000000007
+#define curtime chrono::steady_clock::now().time_since_epoch().count
+#define rep(i, beg, n, s) for (int i = beg; i < n; i += s)
+const double PI = acos(-1);
+
+using namespace std;
+
+inline int mod(int n, int m = M)
+{
+ int ret = n % m;
+ if (ret < 0)
+ ret += m;
+ return ret;
+}
+
+int exp(int n, int k)
+{
+ if (k == 0)
+ return 1;
+ if (k == 1)
+ return n;
+ int ax = exp(n, k / 2);
+ ax = mod(ax * ax);
+ if (k % 2)
+ ax = mod(ax * n);
+ return ax;
+}
+
+int gcd(int a, int b)
+{
+ if (a == 0)
+ return b;
+ else
+ return gcd(b % a, a);
+}
+//#define MULTIPLE_TEST_CASE
+void solution()
+{
+ map<ii, int> m;
+ int ans = 0;
+ int n;
+ cin >> n;
+ for (int i = 0; i < n; i++)
+ {
+ double x;
+ cin >> x;
+ ii frac(round(x * 1e9), 1e9);
+ int g = gcd(frac.ff, frac.ss);
+ frac.ff /= g;
+ frac.ss /= g;
+ int pot5 = 0;
+ int pot2 = 0;
+ while (frac.ff % 2 == 0)
+ {
+ frac.ff /= 2;
+ pot2++;
+ }
+ while (frac.ff % 5 == 0)
+ {
+ frac.ff /= 5;
+ pot5++;
+ }
+ while (frac.ss % 2 == 0)
+ {
+ frac.ss /= 2;
+ pot2--;
+ }
+ while (frac.ss % 5 == 0)
+ {
+ frac.ss /= 5;
+ pot5--;
+ }
+ ii cur(pot5, pot2);
+ for (auto p : m)
+ {
+ if (p.ff.ff + cur.ff >= 0 && p.ff.ss + cur.ss >= 0)
+ ans += p.ss;
+ }
+ m[cur]++;
+ }
+ cout << ans << endl;
+}
+
+int32_t main()
+{
+ DESYNC;
+ mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
+ int t = 1;
+#ifdef MULTIPLE_TEST_CASE
+ cin >> t;
+#endif
+ while (t--)
+ solution();
+}
+