apm.cpp: In function 'void unite(int, int, int)': apm.cpp:42: warning: comparison between signed and unsigned integer expressions apm.cpp:44: warning: comparison between signed and unsigned integer expressions apm.cpp:53: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x apm.cpp:53: warning: extended initializer lists only available with -std=c++0x or -std=gnu++0x apm.cpp: In function 'int main()': apm.cpp:87: warning: comparison between signed and unsigned integer expressions