Compilare: user.cpp: In function ‘void read(int&)’: user.cpp:27:22: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] while(ch>'9'||ch<'0'&&val1>=val2) ^ user.cpp: In function ‘int main()’: user.cpp:102:10: warning: unused variable ‘i’ [-Wunused-variable] for(int i=P;;) ^ user.cpp: In function ‘void read(int&)’: user.cpp:26:23: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file,"%c",&ch); ^ user.cpp:31:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file,"%c",&ch); ^ user.cpp:44:24: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file,"%c",&ch); ^ user.cpp: In function ‘int main()’: user.cpp:93:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("hacker3.out","w",stdout); ^ user.cpp:96:22: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file,"%d",&N); ^