Compilare: user.cpp: In function ‘int extend(int, int)’: user.cpp:16:22: warning: unused variable ‘val’ [-Wunused-variable] int _max = 1, k, val; ^ user.cpp: In function ‘int main()’: user.cpp:31:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &n); ^ user.cpp:40:39: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(in, "%d", &a[i][j]); ^ user.cpp:55:17: warning: ‘y’ may be used uninitialized in this function [-Wmaybe-uninitialized] while(s[x][y] != 1) { ^ user.cpp:55:17: warning: ‘x’ may be used uninitialized in this function [-Wmaybe-uninitialized]