为什么这个程序会生成LIB文件而不是exe

#include<stdio.h> #include<stdlib.h> typedef int datatype; #define MaxSize 5 typedef struct nod { datatype data[MaxSize]; int real ,front; }du; void crealist1(du *one) { one->front=0; one->real=1; one->data[one->front]=NULL; } void crealist(du *one) { while(((one->real)+1/MaxSize)!=one->front) { datatype x; scanf("%d",&x); if(one->data[one->front]=NULL) one->data[one->front]=x; else { one->data[one->real]=x; one->real=one->real+1/MaxSize; } } } void putout(du *one) { while(one->front!=one->real) { printf("%d",one->data[one->front]); one->front=one->front+1/MaxSize; } } int mian() { du *one; one=(du *)malloc(sizeof(du)); crealist1(one); crealist(one); putout(one); return 0; }