Compilare: user.cpp: In function ‘int main()’: user.cpp:21:22: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(s[i]>='a' && s[i]<='z' || s[i]>='A' && s[i]<='Z' || s[i]>='0' && s[i]<='9') ^ user.cpp:21:74: warning: suggest parentheses around ‘&&’ within ‘||’ [-Wparentheses] if(s[i]>='a' && s[i]<='z' || s[i]>='A' && s[i]<='Z' || s[i]>='0' && s[i]<='9') ^ user.cpp:33:41: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<path.size();i++) ^ user.cpp:55:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<path.size();i++) ^ user.cpp:70:45: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<path.size();i++) ^ user.cpp:15:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dir.in","r",stdin); ^ user.cpp:16:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("dir.out","w",stdout); ^ user.cpp:17:28: warning: ignoring return value of ‘char* fgets(char*, int, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fgets(s,MAX_SIZE,stdin); ^