Compilare: main.cpp: In function 'void prec(int)': main.cpp:34:17: warning: array subscript has type 'char' [-Wchar-subscripts] val[s[i]] = 1; ^ main.cpp:38:27: warning: array subscript has type 'char' [-Wchar-subscripts] P[0][i] = val[s[i]] - 1; ^ main.cpp: In function 'void read()': main.cpp:17:37: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("substr.in", "r", stdin); ^ main.cpp:18:29: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d\n", &n, &k); ^ main.cpp:19:19: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s); ^ main.cpp: In function 'void write()': main.cpp:101:39: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("substr.out", "w", stdout); ^