关于#c语言#的问题，请各位专家解答！

#include <stdio.h>
#include <stdlib.h>
typedef struct _sal
{
    char name[20];
    float base;
    float f;
    float out;
}sal;
int main()
{
    sal s[3] = {{"lili",5240,1400,1050},{"wangming",5360,800,750},{"zhanghao",5560,300,580}};
    FILE *fp = fopen("salary.dat","w");
    if(fp != NULL)
    {
        for(int i=0;i<3;i++)
              fprintf(fp,"%s\t%f\n",s[i].name,s[i].base + s[i].f - s[i].out);
        fclose(fp);
    }
    return 0;
}