add GCD3

gcd3.cpp

@@ -0,0 +1,47 @@
+// 2016-07-01
+#include <iostream>
+#include <deque>
+using namespace std;
+typedef deque<int> T;
+bool e(const T& n) {
+    return n.back() % 2 == 0;
+}
+void s(T& n) {
+    int c = 0;
+    for (int i = 0; i < (int)n.size(); i++) {
+        int d = 10*c + n[i];
+        c = d%2;
+        n[i] = d/2;
+    }
+    if (n.front() == 0) {
+        n.pop_front();
+    }
+}
+T f(const string& s) {
+    T r(s.size());
+    for (int i = 0; i < (int)s.length(); i++) {
+        r[i] = s[i] - '0';
+    }
+    return r;
+}
+int main() {
+    ios::sync_with_stdio(false);
+    int t; cin >> t;
+    while (t--) {
+        string P, Q;
+        int K;
+        cin >> P >> Q >> K;
+        T N = f(P), M = f(Q);
+        if (e(N)) {
+            int p = 0;
+            while (p < K && e(N)) {
+                p++;
+                s(N);
+            }
+            cout << (1 << p) << "\n";
+        } else {
+            cout << "1\n";
+        }
+    } 
+    return 0;
+}