Compilare: user.cpp: In function ‘bool isfromstack(std::vector<int>)’: user.cpp:19:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < seq.size(); i++) { ^ In file included from /usr/include/c++/4.8/cassert:43:0, from user.cpp:3: user.cpp: In function ‘bool solve(int*, int, int)’: user.cpp:66:48: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] assert(before.size() + after.size() + n == range); ^ user.cpp:71:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < before.size(); i++) ^ user.cpp:73:53: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = before.size(); i < before.size() + n; i++) ^ user.cpp: In function ‘int main()’: user.cpp:85:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &k); ^ user.cpp:90:35: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &output[i]); ^ user.cpp: In function ‘bool solve(int*, int, int)’: user.cpp:39:35: warning: ‘imax’ may be used uninitialized in this function [-Wmaybe-uninitialized] int i = n + 1, maxright = -1, imax; ^