Compiler output
prog.cpp: In function ‘int main()’:
prog.cpp:57:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses]
prog.cpp:71:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses]
prog.cpp:78:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses]
prog.cpp:85:16: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses]
prog.cpp:89:67: warning: NULL used in arithmetic [-Wpointer-arith]
prog.cpp:91:67: warning: NULL used in arithmetic [-Wpointer-arith]
