Compilare: user.cpp: In function ‘int main()’: user.cpp:27:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[0] = (1.0 + p2[v[1]]) / p1[v[1]]; ^ user.cpp:27:38: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[0] = (1.0 + p2[v[1]]) / p1[v[1]]; ^ user.cpp:29:34: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i] = (1.0 + p2[v[i + 1]] + p3[v[i + 1]] * a[i - 1]) / p1[v[i + 1]]; ^ user.cpp:29:49: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i] = (1.0 + p2[v[i + 1]] + p3[v[i + 1]] * a[i - 1]) / p1[v[i + 1]]; ^ user.cpp:29:76: warning: array subscript has type ‘char’ [-Wchar-subscripts] a[i] = (1.0 + p2[v[i + 1]] + p3[v[i + 1]] * a[i - 1]) / p1[v[i + 1]]; ^ user.cpp:13:30: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%d%d", &n, &k); ^ user.cpp:25:73: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fi,"%lf%lf%lf", &p1['a' + i], &p2['a' + i], &p3['a' + i]); ^