cover.cpp: In member function 'bool interval::operator<(const interval&) const': cover.cpp:22: warning: suggest parentheses around '&&' within '||' cover.cpp: In function 'void read()': cover.cpp:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cover.cpp:41: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cover.cpp:44: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result cover.cpp: In function 'void solve()': cover.cpp:76: warning: comparison between signed and unsigned integer expressions cover.cpp: In function 'int main()': cover.cpp:88: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result cover.cpp:89: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result