C语言输入年份换算成年龄输出

年龄那里怎么把年份计算出年龄
如图代码%d那里输入年份 下面years old前面怎么显示年龄

printf("Enter your friends' year of birth:\n");
scanf("%d", &age);
printf("Your friends is %d years old and %.2lf kgs in weight.\n", age, weight);

#include<stdio.h>
int main()
{
    int y0,m0,d0;
    int y1,m1,d1;
    int y,m,d;
    printf("请输入学生的生日(年：y0.月：m0.日：d0)\n");
    printf("请输入当前日期(年：y0.月：m0.日：d0)\n");
    scanf("%d%d%d",&y0,&m0,&d0);
    scanf("%d%d%d",&y1,&m1,&d1);
    if(d1<d0)
        {
            m1--;//m1=m1-1,m1-=1
            switch(m1)
            {
            case 2:d=d1+28-d0;break;
            case 4:d=d1+30-d0;break;
            case 6:d=d1+30-d0;break;
            case 9:d=d1+30-d0;break;
            case 11:d=d1+30-d0;break;
            }
        }
    else
            d=d1-d0;
    if(m1<m0)
        {
        y1--;
        m=m1+12-m0;
        }
    else
        {
        m=m1-m0;
        y=y1-y0;
        }

printf("实际年龄为：年=%d,月=%d,日=%d",y,m,d);
return 0;
}

#include<stdio.h>
int main()
{
    int y0, m0, d0;
    int y1, m1, d1;
    int age = 0;
    printf("请输入学生的生日(年：y0.月：m0.日：d0)\n");
    printf("请输入当前日期(年：y0.月：m0.日：d0)\n");
    scanf("%d%d%d", &y0, &m0, &d0);
    scanf("%d%d%d", &y1, &m1, &d1);
    if (y1 > y0)
    {
        age = y1 - y0;
        if (m1 < m0) age -= 1;
        else if (m1 == m0 && d1 < d0) age -= 1;
    }
    printf("%d",age);
}