add@scpc 2025-1s

storage/scpc/cpp/completed/2025-1-3.cpp

@@ -0,0 +1,93 @@
+#include <iostream>
+
+using namespace std;
+
+constexpr long long MOD = 1000000007;
+
+int POW3[100001];
+
+int get_count_decimal_012(const string &s) {
+    auto n = s.size();
+
+    if (n == 1) { if (s[0] == '1') { return 1; } else { return 2; } }
+
+    auto cnt = 0LL;
+
+    // f (1 until 10^(n-1))을 구하기
+    auto temp = 1LL;
+    POW3[0] = temp;
+    for (auto i = 1; i <= (n - 1); i++) {
+        temp *= 3;
+        temp %= MOD;
+        POW3[i] = temp;
+    }
+
+
+    temp += MOD - 1;
+    temp %= MOD;
+
+    cnt += temp;
+    cnt %= MOD;
+
+    // f(10^(n-1) to int(s)) 까지 구하기
+    if (s[0] == '0') {
+        // pass
+    } else if (s[0] == '1') {
+        // pass
+    } else if (s[0] == '2') {
+        long long tmpx = POW3[n - 1];
+        cnt += tmpx;
+        cnt %= MOD;
+    } else {
+        long long tmpx = POW3[n - 1];
+        tmpx *= 2;
+        cnt += tmpx;
+        cnt %= MOD;
+        return static_cast<int>(cnt);
+    }
+
+    bool flag = false;
+    for (int i = 1; i < n; i++) {
+        auto ch = s[i];
+        if (ch == '0') { continue; } else if (ch == '1') {
+            long long tmpx = POW3[n - i - 1];
+            cnt += tmpx;
+            cnt %= MOD;
+        } else if (ch == '2') {
+            long long tmpx = 2 * POW3[n - i - 1];
+            cnt += tmpx;
+            cnt %= MOD;
+        } else {
+            long long tmpx;
+
+            tmpx = POW3[n - i];
+
+            cnt += tmpx;
+            cnt %= MOD;
+            flag = true;
+            break;
+        }
+    }
+
+    if (!flag) {
+        cnt++;
+        cnt %= MOD;
+    }
+
+    return static_cast<int>(cnt);
+}
+
+int main() {
+    ios_base::sync_with_stdio(false);
+    std::cin.tie(nullptr);
+
+    int t;
+    cin >> t;
+    for (auto test_case = 1; test_case <= t; test_case++) {
+        string s;
+        cin >> s;
+
+        cout << "Case #" << test_case << endl;
+        cout << get_count_decimal_012(s) << endl;
+    }
+}