hdu2080
计算两点关于原点夹角,数学
1 #include<stdio.h>
2 #include<math.h>
3 double len(double x1,double y1,double x2,double y2){
4 return sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
5 }
6 int main(){
7 int T;
8 while(scanf("%d",&T)!=EOF){
9 for(int q=1;q<=T;q++){
10 double x1,y1,x2,y2;
11 double a,b,c;
12 scanf("%lf%lf%lf%lf",&x1,&y1,&x2,&y2);
13 a=len(0,0,x1,y1);
14 b=len(0,0,x2,y2);
15 c=len(x1,y1,x2,y2);
16 double cos1=(a*a+b*b-c*c)/(2*a*b);
17 double t=acos(cos1)*180/3.14159;
18 printf("%.2lf
",t);
19 }
20 }
21 return 0;
22 }
hdu2081
模拟
1 #include<stdio.h>
2
3 int main(){
4 int N;
5 while(scanf("%d",&N)!=EOF){
6 for(int q=1;q<=N;q++){
7 char a[12];
8 scanf("%s",a);
9 printf("6");
10 for(int i=6;i<=10;i++)printf("%c",a[i]);
11 printf("
");
12 getchar();
13 }
14 }
15 return 0;
16 }