Compilare: main.cpp: In function 'int main()': main.cpp:50:10: warning: statement has no effect [-Wunused-value] for(t;t;--t){ ^ main.cpp:70:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(ok && sol.size() == 2*n){ ~~~~~~~~~~~^~~~~~ main.cpp:46:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dungeon.in","r",stdin); ^ main.cpp:47:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("dungeon.out","w",stdout); ^ main.cpp:49:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&t); ^ main.cpp:51:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ main.cpp:54:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^ main.cpp:63:33: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &x,&y); ^