View Compilation Error

0_0_30174736_5460.cpp: In function 'int main()':
0_0_30174736_5460.cpp:25:24: error: 'strlen' was not declared in this scope
    if (j == strlen(str2))
                        ^
0_0_30174736_5460.cpp:34:29: error: 'memset' was not declared in this scope
   memset(str1, '\0', 1000000);
                             ^