Compilare: user.cpp: In function ‘int getKey(char*)’: user.cpp:26:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] key = key*12 + prior[s[i]]; ^ user.cpp: In function ‘int main()’: user.cpp:40:18: warning: array subscript has type ‘char’ [-Wchar-subscripts] prior[sym] = i; ^ user.cpp:31:32: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(inFile, "r", stdin); ^ user.cpp:32:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen(outFile, "w", stdout); ^ user.cpp:37:37: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &solveType, &n); ^ user.cpp:39:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%c", &sym); ^ user.cpp:43:14: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ user.cpp:46:18: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(str); ^ /tmp/ccRHQMND.o: In function `main': user.cpp:(.text.startup+0xa5): warning: the `gets' function is dangerous and should not be used.