Compilare: user.cpp: In function ‘int main()’: user.cpp:21:13: warning: unused variable ‘k’ [-Wunused-variable] int i, j, k, d, a, b; ^ user.cpp:21:22: warning: unused variable ‘b’ [-Wunused-variable] int i, j, k, d, a, b; ^ user.cpp:22:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &N); ^ user.cpp:23:25: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%s", s + 1); ^ user.cpp:26:32: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f, "%d", &c[i][j]); ^ user.cpp:142:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("redu.out", "w", stdout); ^