0_0_23407020_29627.cpp: In function 'int main()': 0_0_23407020_29627.cpp:13:21: error: 'strlen' was not declared in this scope n = strlen(a); ^ 0_0_23407020_29627.cpp:15:29: error: 'memset' was not declared in this scope memset(c,0,sizeof(c)); ^