Compilare: user.c: In function ‘main’: user.c:21:5: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration] for(i=0; i<=strlen(ecuatie); i++){ ^ user.c:21:17: warning: incompatible implicit declaration of built-in function ‘strlen’ [enabled by default] for(i=0; i<=strlen(ecuatie); i++){ ^ user.c:23:9: warning: implicit declaration of function ‘isdigit’ [-Wimplicit-function-declaration] if(isdigit(ecuatie[i])){ ^ user.c:68:5: warning: format ‘%f’ expects argument of type ‘double’, but argument 3 has type ‘int’ [-Wformat=] fprintf(file2, "%.4f\n", 0); ^ user.c:7:11: warning: unused variable ‘isAnX’ [-Wunused-variable] int N, i, isAnX; ^ user.c:15:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%d", &N); ^ user.c:19:7: warning: ignoring return value of ‘fscanf’, declared with attribute warn_unused_result [-Wunused-result] fscanf(file1, "%s", ecuatie); ^