pasune.cpp: In function 'int main()': pasune.cpp:35: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result pasune.cpp:37: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pasune.cpp:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result pasune.cpp: In function 'void prim()': pasune.cpp:15: warning: 'k' may be used uninitialized in this function