#include main(){ int n,i; float c,s,a,b; while(scanf("%d",&n)!=EOF) {s=0.75; a=3; b=2; i=0;//////初始化i为0 s =0.0;//////初始化s为0 while(i<=n) { a=a*(a+2); b=(b+2)*(b+2); c=a/b; s=s+c; i++; } printf("%.5f\n",s); }}
在 while(i<=n)之前应给i赋值2