在线编译器 C

#include <stdio.h> int main() { int x,y,z,s; scanf("%d%d%d%d,&x,&y,&z,&s") x=sum/100 y=(sum%100)/10 z=(sum%10) s=x+y+z printf("%d\n",s) return 0; }
The code attempts to read four integers, but the variable `sum` is used without being defined, and the logic for calculating digits is unclear. The `scanf` call has a syntax error with the closing parenthesis and quotation mark placement.

- The `scanf` function call is missing a closing parenthesis and the format string is not properly closed. Check the syntax of the `scanf` line.
- The variable `sum` is used in calculations but never declared or assigned a value. Decide what value you want to split into digits and assign it to a variable first.