/in/l6.c: In function 'l6':
/in/l6.c:59:13: error: implicit declaration of function 'strcpy' [-Werror=implicit-function-declaration]
             strcpy(path + 6, file->d_name);
             ^~~~~~
/in/l6.c:59:13: error: incompatible implicit declaration of built-in function 'strcpy' [-Werror]
/in/l6.c:59:13: note: include '<string.h>' or provide a declaration of 'strcpy'
/in/l6.c:76:17: error: implicit declaration of function 'strcmp' [-Werror=implicit-function-declaration]
             if (strcmp(hall[k].name, output[i].hall_name) == 0){
                 ^~~~~~
/in/l6.c:79:24: error: unused variable 'center' [-Werror=unused-variable]
                 double center = (hall[k].n + 1) / 2.;   //'.'!!!!!??????
                        ^~~~~~
cc1: all warnings being treated as errors