skyscraper.cpp: In function 'int go(int, int, int)':
skyscraper.cpp:26:21: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
if ((mask >> i) & 1 ^ 1) continue;
~~~~~~~~~~~~^~~
skyscraper.cpp: At global scope:
skyscraper.cpp:35:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
main() {
^
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:37:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &n, &l);
~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:39:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &a[i]);
~~~~~^~~~~~~~~~~~~