feat: 添加实现四舍五入的C++算法

Author: tkzzzzzz6

niuke/problems/编程入门-C/CPP2.实现四舍五入.cpp

@@ -0,0 +1,54 @@
+/*
+ * @Author: tkzzzzzz6
+ * @Date: 2026-04-28 09:41:21
+ * @LastEditors: tkzzzzzz6
+ * @LastEditTime: 2026-04-28 09:41:40
+ */
+/**
+ * @nc app=nowcoder id=020a0cf673174d5795d97ae79cff59a0 topic=225 question=2177130 lang=C++
+ * 2026-04-28 09:41:21
+ * https://www.nowcoder.com/practice/020a0cf673174d5795d97ae79cff59a0?tpId=225&tqId=2177130
+ * [CPP2] 实现四舍五入
+ */
+
+/** @nc code=start */
+
+#include<bits/stdc++.h>
+#define il inline
+#define endl '\n'
+using namespace std;
+
+#define pb push_back
+#define fastio \
+ios::sync_with_stdio(false); \
+cin.tie(0);
+
+typedef long long ll;
+typedef unsigned long long ull;
+
+const ll N = 5e5+5, mod = 1e9+7, inf = 2e18;
+const double eps = 1e-9;
+const double PI = 3.1415926;
+
+il void solve(){
+    double t;
+    cin >> t;
+    cout << round(t) << endl;
+    // cout << (long long)(t + 0.5); //只适用非负数
+}
+
+int main()
+{
+    fastio;
+    
+    int t = 1;
+    // cin >> t;
+    while(t--)
+    {
+        solve();
+    }
+    
+    return 0;
+}
+
+/** @nc code=end */