zoo.cpp: In function `void build(int, int, int)': zoo.cpp:18: warning: comparison between signed and unsigned integer expressions zoo.cpp:29: warning: comparison between signed and unsigned integer expressions zoo.cpp:29: warning: comparison between signed and unsigned integer expressions zoo.cpp:42: warning: comparison between signed and unsigned integer expressions zoo.cpp:44: warning: comparison between signed and unsigned integer expressions /tmp/ccBdxTMP.o(.text+0x50f): In function `main': : the `gets' function is dangerous and should not be used.