Compilare: user.cpp: In function ‘int main()’: user.cpp:64:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d%d ", &n, &m); ^ user.cpp:65:25: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s, MAXM + 2, in); ^ user.cpp:62:22: warning: ‘b’ may be used uninitialized in this function [-Wmaybe-uninitialized] int n, m, i, j, a, b, l; ^ user.cpp:79:24: warning: ‘a’ may be used uninitialized in this function [-Wmaybe-uninitialized] j = (m - i * b) / a; ^