diff --git a/day6/homework/h4.cpp b/day6/homework/h4.cpp
new file mode 100644
index 0000000..91f0df6
--- /dev/null
+++ b/day6/homework/h4.cpp
@@ -0,0 +1,17 @@
+#include <iostream>
+#include <bitset>
+
+using namespace std;
+
+int main()
+{
+    char x = 0b01011011; // char 正好是八位
+
+    cout << "原值为: " << bitset<8>(x) << endl;
+    int n;
+    cout << "请输入要修改的位: ";
+    cin >> n;
+    x ^= (0x1 << n); // 作用: 将第 n 位设置为 0
+    cout << "修改后为: " << bitset<8>(x) << endl;
+    return 0;
+}
\ No newline at end of file