links.cpp: In function 'void stringConversion(std::string&)': links.cpp:24: warning: comparison between signed and unsigned integer expressions links.cpp: In function 'void dfs(int)': links.cpp:33: warning: comparison between signed and unsigned integer expressions links.cpp: In function 'int main()': links.cpp:82: warning: comparison between signed and unsigned integer expressions links.cpp:137: warning: comparison between signed and unsigned integer expressions links.cpp:193: warning: comparison between signed and unsigned integer expressions links.cpp:203: warning: comparison between signed and unsigned integer expressions links.cpp:41: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result links.cpp:42: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result links.cpp:45: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result links.cpp:54: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result links.cpp:69: warning: ignoring return value of 'char* gets(char*)', declared with attribute warn_unused_result /tmp/ccZImKww.o: In function `main': links.cpp:(.text+0x3f9): warning: the `gets' function is dangerous and should not be used.