dragoni.cpp: In function 'void dijkstra()': dragoni.cpp:37: warning: comparison between signed and unsigned integer expressions dragoni.cpp: In function 'int main()': dragoni.cpp:54: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result dragoni.cpp:55: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result dragoni.cpp:56: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result dragoni.cpp:57: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result dragoni.cpp:58: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result dragoni.cpp:60: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result