new file: P5657.cpp

P5657.cpp

@@ -0,0 +1,32 @@
+#include <bits/stdc++.h>
+using namespace std;
+int n;
+unsigned long long k;
+unsigned long long p2[100];
+string gr(int now, unsigned long long k)
+{
+    if (now == 1)
+    {
+        if (k == 0)
+            return "0";
+        else
+            return "1";
+    }
+    if (k < p2[now - 1])
+    {
+        return "0" + gr(now - 1, k);
+    }
+    else
+    {
+        return "1" + gr(now - 1, p2[now] - k - 1);
+    }
+}
+int main()
+{
+    p2[0] = 1;
+    for (int i = 1; i <= 99; ++i)
+        p2[i] = p2[i - 1] * 2;
+    scanf("%d%llu", &n, &k);
+    cout << gr(n, k);
+    return 0;
+}