By looking at them i would like say there is no error.
Here ans is #include<stdio.h> which is not appropriate but compared to other .Now See
int n=17; //No error since int value
char c=99 ;// char even take int so no error
float=(float)99.32 //No error float is type-casting
#include<stdio.h>//If you have single statement"#include<stdio.h>" Compiler Simply generate error Undefined reference to main()