Compilare: main.cpp: In function 'bool check(char)': main.cpp:21:16: warning: suggest parentheses around comparison in operand of '==' [-Wparentheses] return a[0]==a[4]==a[8] || a[2]==a[4]==a[6]; ~~~~^~~~~~ main.cpp:21:36: warning: suggest parentheses around comparison in operand of '==' [-Wparentheses] return a[0]==a[4]==a[8] || a[2]==a[4]==a[6]; ~~~~^~~~~~ main.cpp: In function 'int main()': main.cpp:73:40: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("xsizero.out", "w", stdout); ^