Compilare: user.cpp: In function ‘int main()’: user.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x<= 1<<(n-1) && y<= 1<<(n-1)){ ^ user.cpp:19:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(x<= 1<<(n-1) && y<= 1<<(n-1)){ ^ user.cpp:30:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x<= 1<<(n-1) && y> 1<<(n-1)){ ^ user.cpp:30:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x<= 1<<(n-1) && y> 1<<(n-1)){ ^ user.cpp:43:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x> 1<<(n-1) && y<= 1<<(n-1)){ ^ user.cpp:43:43: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x> 1<<(n-1) && y<= 1<<(n-1)){ ^ user.cpp:56:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x> 1<<(n-1) && y> 1<<(n-1)){ ^ user.cpp:56:42: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] else if(x> 1<<(n-1) && y> 1<<(n-1)){ ^ user.cpp:8:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("z.in", "r", stdin); ^ user.cpp:9:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("z.out", "w", stdout); ^ user.cpp:11:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &n, &k); ^ user.cpp:17:30: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x,&y); ^