Compilare: user.cpp: In function ‘int main()’: user.cpp:73:18: warning: unused variable ‘j’ [-Wunused-variable] int n, m, i, j, x, y; ^ user.cpp: In function ‘char nextch()’: user.cpp:12:34: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf, 1, MAXBUF, fi); ^