int i;int sum=0;for(i=1;;i++){ sum=(1+i)*i/2;if(sum>1000)break;} printf("n的最小值为:%d,其和为:%d",i,sum);getch();}
printf("%d %d\n",i,sum);} printf("sum=%d\n",sum);return 0;} 整除特征 1. 若一个数的末位是单偶数,则这个数能被2整除。2. 若一个数的所有数位上的数字和能被3整除,则这个整数能被3整除。3. 若一个数的末尾两位数能被4整除,则这个数能被4整除。4. 若一个数的末位是0或5...
return 1;else return (num * factorial(num - 1));} int main(){ int i,n;long sum = 1;scanf("%d",&n);for (i = 2;i <= n;++i)sum += factorial(i);printf("%ld\n",sum);return 0;}
先写出一个如下的函数:int fun(int n){ int s=1;for(int i=1;i<=n;i++)s*=i;return s;} 然后在主函数中调用反复调用它 int main(){ int n;while(cin>>n){ int sum=0;for(int i=1;i<=n;i++){ sum+=fun(i);} cout<<sum<<endl;} } ...
} printf("%d项之和为:%d\n",n,sum); return 0;}int slSum(int n)//数列求和1+2+3...n 返回和{ int i=1,sum=0; for(i=1;i<n;i++) { sum=sum+i; printf("%d+",i); } sum=sum+i; printf("%d,"...
include <stdio.h> int main(){ unsigned long n,i,sum,t;scanf("%lu",&n);for(t=i=1,sum=0;i<=n;++i){ sum+=t*=i;} printf("%lu\n",sum);return 0;} 请点击输入图片描述
include<stdio.h> int main(){ int i,n,m=0,s=0;printf("Please input the number:\n");scanf("%d",&n);printf("n=%d\n",n);for(i=1;i<n+1;i++){ m+=i;s+=m;} printf("s=%d\n",s);return 0;}
include stadio.h;void main(){ int i,sum=0;for(i=1;i<=100;i++){ sum=sum+i;} printf("1+2+3+...+100=",&sum);}
1+2+3+……+n=0.5n(n+1)>100 随着n的增大而增大。可以尝试几个n值,n=14 0.5n(n+1)=0.5*14*15=105 n=13 0.5n(n+1)=0.5*13*14=91 所以:n=14