程序代码：

#include <stdio.h>
#include <string.h>
int main(void) {
    char name[40];
    int width;
    printf("请输入你的名字：\n");
    scanf("%s", name);
    printf("\"%s\"\n", name);
    printf("\"%20s\"\n", name);
    printf("\"%-20s\"\n", name);
    width = strlen(name) + 3;
    printf("%d\n", width);
    //在比名字宽3个字符的字段内打印名字

    return 0;
}