int main()
{
??? /* 小伙伴們：
?????????? 選擇你們認(rèn)為最合理的循環(huán)結(jié)構(gòu)完成功能吧 */
??? int sum = 0;? //定義計(jì)算結(jié)果變量sum
??? int i = 1;??? //定義循環(huán)數(shù)字變量i
??? int flag = 1; //定義符號(hào)狀態(tài)變量flag
?? ?
??? //使用while循環(huán)
??? while(i<=100)
??? {
??????? i++;
??????? sum+=i*flag;
??????? flag*=-1;
??? }
?? ?
??? i = 1;? //重新初始化變量i
??? printf("sum=%d\n",sum);
?? ?
??? return 0;?? ?
??? //do-while循環(huán)
??? do{
??????? i++;
??????? sum+=i*flag;
??????? flag*=-1;
??? }while(i<=100);
?? ?
??? i = 1;? //重新初始化變量i
??? printf("sum=%d\n",sum);
?? ?
??? return 0;?? ?
??? //使用for循環(huán)
??? for(i=1;i<=100;i++)
??? {
??????? sum+=i*flag;
??????? flag*=-1;
??? } ?
??? printf("sum=%d\n",sum);
?? ?
??? return 0;?? ?
}