Compilare: user.cpp: In function ‘int main()’: user.cpp:31:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i+1] = (a[i] - pi[c] * a[i] - pb[c] * a[i-1]) / pc[c]; ^ user.cpp:31:45: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i+1] = (a[i] - pi[c] * a[i] - pb[c] * a[i-1]) / pc[c]; ^ user.cpp:31:63: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i+1] = (a[i] - pi[c] * a[i] - pb[c] * a[i-1]) / pc[c]; ^ user.cpp:32:30: warning: array subscript has type ‘char’ [-Wchar-subscripts] b[i+1] = (b[i] - pi[c] * (2 + b[i]) - pb[c] * (1 + b[i-1]) - pc[c]) / pc[c]; ^ user.cpp:32:51: warning: array subscript has type ‘char’ [-Wchar-subscripts] b[i+1] = (b[i] - pi[c] * (2 + b[i]) - pb[c] * (1 + b[i-1]) - pc[c]) / pc[c]; ^ user.cpp:32:74: warning: array subscript has type ‘char’ [-Wchar-subscripts] b[i+1] = (b[i] - pi[c] * (2 + b[i]) - pb[c] * (1 + b[i-1]) - pc[c]) / pc[c]; ^ user.cpp:32:83: warning: array subscript has type ‘char’ [-Wchar-subscripts] b[i+1] = (b[i] - pi[c] * (2 + b[i]) - pb[c] * (1 + b[i-1]) - pc[c]) / pc[c]; ^ user.cpp:15:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sms.in", "r", stdin); ^ user.cpp:16:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sms.out", "w", stdout); ^ user.cpp:18:28: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n", &n, &k); ^ user.cpp:19:19: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%s", s); ^ user.cpp:22:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lf%lf%lf", &pc[i], &pi[i], &pb[i]); ^