题解 | #平均年龄#

#include <stdio.h>
#include <math.h>
float getage(int w,float y,double x,int newage)
{
	return (1-x)*(y+1)+x*newage;
}
int main()
{
    int w,n;
    float x,y;
    while(scanf("%d %f %f %d",&w,&y,&x,&n)!=EOF){
        float answer;
        while(n>0)
        {
            answer=getage(w,y,x,21);
            y=answer;
            n--;
        }
        int a=ceil(answer);
        printf("%d\n",a);
    }
    return 0;
}