参考程序: 1. #include <iostream . h> void main(t int year, leap: cou<"输入一年号: if(year%400=0)leap=l else if(year%4==0&&year%1001=0)leap=l else leap=0; if(leap)cout<<year<<"是闰年n else cout<<year<<"不是闰年n"; 2. #include <iostream. h void main(i Int s while(1)i cout<<"请输入百分制分数:" switch(s/10) case9:cout<<"五分制分数为An", break case8:cout<<"五分制分数为Bln" break case7cout<<"五分制分数为Cun"; break case6cout<<"五分制分数为Dn" break default cout<<"五分制分数为En" break参考程序： 1．#include <iostream.h> void main(){ int year,leap; cout<<"输入一年号："; cin>>year; if(year%400==0)leap=1; else if(year%4==0&&year%100!=0)leap=1; else leap=0; if(leap)cout<<year<<"是闰年\n"; else cout<<year<<"不是闰年\n"; } 2．#include <iostream.h> void main(){ int s; while(1){ cout<<"请输入百分制分数："; cin>>s; if(s<=0)break; switch(s/10){ case 10: case 9:cout<<"五分制分数为 A\n";break; case 8:cout<<"五分制分数为 B\n";break; case 7:cout<<"五分制分数为 C\n";break; case 6:cout<<"五分制分数为 D\n";break; default:cout<<"五分制分数为 E\n";break; } } }