2023 rcpc

2023/rcpc/d2/editorial/e-fiboxor-52.cpp

@@ -0,0 +1,60 @@
+#include <bits/stdc++.h>
+
+using namespace std;
+
+#define int long long
+
+int l,r,m;
+
+int lgpow(int x,int y)
+{
+    int z = 1;
+    while (y != 0)
+    {
+        if (y % 2 == 1)
+            z = z * x % m;
+        x = x * x % m;
+        y /= 2;
+    }
+    return z;
+}
+
+int sump2(int x)
+{
+    return lgpow(2,x + 1) - 1;
+}
+
+void testcase()
+{
+    cin >> l >> r >> m;
+    int ans = 0;
+    if (r - l + 1 <= 3)
+    {
+        for (int i = l; i <= r; i++)
+            ans += lgpow(2,(i - 1) / 2);
+        cout << ans % m << '\n';
+    }
+    else
+    {
+        if (l % 2 == 0)
+            ans += lgpow(2,(l - 1) / 2),l++;
+        if (r % 2 == 1)
+            ans += lgpow(2,(r - 1) / 2),r--;
+        int st = (l + 1) / 2,fin = (r / 2);
+        ans += sump2(fin) - sump2(st - 1);
+        ans += m;
+        cout << ans % m << '\n';
+    }
+}
+
+signed main()
+{
+    ios_base::sync_with_stdio(false);
+    cin.tie(NULL);
+    cout.tie(NULL);
+    int tc;
+    cin >> tc;
+    while (tc--)
+        testcase();
+    return 0;
+}