View Compilation Error

0_0_13642380_20313.cpp: In function 'int main()':
0_0_13642380_20313.cpp:10:29: error: 'memset' was not declared in this scope
   memset(flag,0,sizeof(flag));//初始化，全部标为0
                             ^
0_0_13642380_20313.cpp: At global scope:
0_0_13642380_20313.cpp:42:2: error: expected unqualified-id before '/' token
 */
  ^
0_0_13642380_20313.cpp:42:2: error: expected constructor, destructor, or type conversion before '/' token
0_0_13642380_20313.cpp: In function 'int main()':
0_0_13642380_20313.cpp:49:5: error: redefinition of 'int main()'
 int main()
     ^
0_0_13642380_20313.cpp:4:5: note: 'int main()' previously defined here
 int main()
     ^