1049.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <ctype.h>
double f(int n){
	return n<=1?1:n*f(n-1);
}
int main(){
	char str[100]={0};
	while(~scanf("%s",str)){
		int count=0;
		while(str[count])str[count++]=tolower(str[count]);
		if(strcmp(str,"sin")&&strcmp(str,"cos")){
			printf("Input Error.\n");
			memset(str,0,sizeof(str));
			continue;
		}
		double x;
		int neg=0,n;
		scanf("%lf%d",&x,&n);
		while(x>=360 || x<0){
			if(x>=360)
				x-=360;
			else if(x<0)
				x+=360;
		}
		if(x>=180) {
			x-=180;
			neg=1;
		}
		double r=x*3.14/180,s=0.0;
		if(!strcmp(str,"sin")){
			for(int i=0;i<=n;i++)
				s+=pow(-1,i)*powl(r,2*i+1)/f(2*i+1);
			if(neg)s*=-1;
			printf("%lf\n",s);
		}
		else if(!strcmp(str,"cos")){
			for(int i=0;i<=n;i++)
				s+=pow(-1,i)*powl(r,2*i)/f(2*i);
			if(neg)s*=-1;
			printf("%lf\n",s);
		}
		memset(str,0,sizeof(str));
	}
	return 0;
}