auto.cpp: In function 'int main()': auto.cpp:22: warning: operation on 'i' may be undefined auto.cpp:22: warning: operation on 'i' may be undefined auto.cpp:25: warning: operation on 'i' may be undefined auto.cpp:25: warning: operation on 'i' may be undefined auto.cpp:25: warning: operation on 'i' may be undefined auto.cpp:9: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result auto.cpp:11: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result auto.cpp:14: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result