Language: C

bool judgeSeven_100(int input){
	int hundredsPlace = input / 100;
  	bool isSeven = false;
  
  if(hundredsPlace == 7){
  	isSeven = true;
  }
  	
  return isSeven;
}

bool judgeSeven_10(int input){
	int tensPlace = (input % 100) / 10;
  bool isSeven = false;
  
  if(tensPlace == 7){
    isSeven = true;
  }
  
	return isSeven;
}

bool judgeSeven_1(int input){
	int onesPlace = (input % 10);
  bool isSeven = false;
  
  if(onesPlace == 7){
  	isSeven = true;
  }

  return isSeven;
}

int main(void){
  int input;
  string output = "No";
  
  cin >> input;
  
  if(judgeSeven_100() == true){
    output = "YES";
  }
  else if(judgeSeven_10() == true){
  	output = "YES";
  }
  else if(judgeSeven_1() == true){
    output = "YES";
  }
  
  cout << output;
  
  return 0;
}  

Compiler output:
main.c:1:1: error: unknown type name 'bool'
    1 | bool judgeSeven_100(int input){
      | ^~~~
main.c:1:1: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
  +++ |+#include <stdbool.h>
    1 | bool judgeSeven_100(int input){
main.c: In function 'judgeSeven_100':
main.c:3:9: error: unknown type name 'bool'
    3 |         bool isSeven = false;
      |         ^~~~
main.c:3:9: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:3:24: error: 'false' undeclared (first use in this function)
    3 |         bool isSeven = false;
      |                        ^~~~~
main.c:3:24: note: 'false' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:3:24: note: each undeclared identifier is reported only once for each function it appears in
main.c:6:19: error: 'true' undeclared (first use in this function)
    6 |         isSeven = true;
      |                   ^~~~
main.c:6:19: note: 'true' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c: At top level:
main.c:12:1: error: unknown type name 'bool'
   12 | bool judgeSeven_10(int input){
      | ^~~~
main.c:12:1: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c: In function 'judgeSeven_10':
main.c:14:3: error: unknown type name 'bool'
   14 |   bool isSeven = false;
      |   ^~~~
main.c:14:3: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:14:18: error: 'false' undeclared (first use in this function)
   14 |   bool isSeven = false;
      |                  ^~~~~
main.c:14:18: note: 'false' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:17:15: error: 'true' undeclared (first use in this function)
   17 |     isSeven = true;
      |               ^~~~
main.c:17:15: note: 'true' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c: At top level:
main.c:23:1: error: unknown type name 'bool'
   23 | bool judgeSeven_1(int input){
      | ^~~~
main.c:23:1: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c: In function 'judgeSeven_1':
main.c:25:3: error: unknown type name 'bool'
   25 |   bool isSeven = false;
      |   ^~~~
main.c:25:3: note: 'bool' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:25:18: error: 'false' undeclared (first use in this function)
   25 |   bool isSeven = false;
      |                  ^~~~~
main.c:25:18: note: 'false' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:28:19: error: 'true' undeclared (first use in this function)
   28 |         isSeven = true;
      |                   ^~~~
main.c:28:19: note: 'true' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c: In function 'main':
main.c:36:3: error: unknown type name 'string'
   36 |   string output = "No";
      |   ^~~~~~
main.c:36:19: error: initialization of 'int' from 'char *' makes integer from pointer without a cast [-Wint-conversion]
   36 |   string output = "No";
      |                   ^~~~
main.c:38:3: error: 'cin' undeclared (first use in this function)
   38 |   cin >> input;
      |   ^~~
main.c:40:6: error: too few arguments to function 'judgeSeven_100'
   40 |   if(judgeSeven_100() == true){
      |      ^~~~~~~~~~~~~~
main.c:1:6: note: declared here
    1 | bool judgeSeven_100(int input){
      |      ^~~~~~~~~~~~~~
main.c:40:26: error: 'true' undeclared (first use in this function)
   40 |   if(judgeSeven_100() == true){
      |                          ^~~~
main.c:40:26: note: 'true' is defined in header '<stdbool.h>'; this is probably fixable by adding '#include <stdbool.h>'
main.c:41:12: error: assignment to 'int' from 'char *' makes integer from pointer without a cast [-Wint-conversion]
   41 |     output = "YES";
      |            ^
main.c:43:11: error: too few arguments to function 'judgeSeven_10'
   43 |   else if(judgeSeven_10() == true){
      |           ^~~~~~~~~~~~~
main.c:12:6: note: declared here
   12 | bool judgeSeven_10(int input){
      |      ^~~~~~~~~~~~~
main.c:44:16: error: assignment to 'int' from 'char *' makes integer from pointer without a cast [-Wint-conversion]
   44 |         output = "YES";
      |                ^
main.c:46:11: error: too few arguments to function 'judgeSeven_1'
   46 |   else if(judgeSeven_1() == true){
      |           ^~~~~~~~~~~~
main.c:23:6: note: declared here
   23 | bool judgeSeven_1(int input){
      |      ^~~~~~~~~~~~
main.c:47:12: error: assignment to 'int' from 'char *' makes integer from pointer without a cast [-Wint-conversion]
   47 |     output = "YES";
      |            ^
main.c:50:3: error: 'cout' undeclared (first use in this function)
   50 |   cout << output;
      |   ^~~~