B3871 [GESP202309 五级] 因数分解

https://www.luogu.com.cn/record/174741748

Luogu/B3871/B3871.cpp

@@ -0,0 +1,42 @@
+#include <iostream>
+#include <cmath>
+
+using std::cin;
+using std::cout;
+const char endl = '\n';
+
+long long n;
+bool flag;
+
+int main() {
+    std::ios::sync_with_stdio(false);
+    cin.tie(nullptr);
+
+    cin >> n;
+
+    long long x = n;
+
+    for (long long i = 2; i <= std::sqrt(n); i++) {
+        if (x % i == 0) {
+            int cnt = 0;
+
+            while (x % i == 0) x /= i, cnt++;
+
+            if (flag) cout << " * ";
+            else flag = true;
+
+            if (cnt > 1) {
+                cout << i << '^' << cnt;
+            } else {
+                cout << i;
+            }
+        }
+    }
+
+    if (x > 1) {
+        if (flag) cout << " * ";
+        cout << x;
+    }
+
+    return 0;
+}