Compilare: user.cpp: In function ‘void build(int, int, int)’: user.cpp:24:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1 < A[2*nod].size() && i2 < A[2*nod+1].size()) { ^ user.cpp:24:61: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i1 < A[2*nod].size() && i2 < A[2*nod+1].size()) { ^ user.cpp:33:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i1<A[(nod<<1)].size();i1++) ^ user.cpp:36:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (;i2<A[(nod<<1)+1].size();i2++) ^ user.cpp: In function ‘int main()’: user.cpp:101:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &n); ^ user.cpp:104:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &v[i]); ^ user.cpp:110:26: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin, "%d", &m); ^ user.cpp:113:30: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(s, 1, 2000000, fin); ^