到2000#include<>#include<>voidmain{inti,j,k,n=0;for(i=10000;i<=20000;i++){k=sqrt(i);for(j=2;j<=k;j++)if(i%j==0)break;if(j>k)n++;}printf("%d\n",n);}2150035#include<>intmain(){inti,n=0,sum=0;for(i=1;i<=500;i++){if(i%3==0||i%5==0)n++;}printf("%d\n",n);return0;}31+（1+2）+（1+2+3）+……100#include<>intmain(){inti,n=0,sum=0;for(i=1;i<=100;i++){n+=i;sum+=n;}printf("%d\n",sum);return0;}求最大水仙花數(shù)#include<>voidmain(){intn;inta,b,c;for(n=999;n>=100;n--){a=n/100;b=(n-100*a)/10;c=n%10;if(n==a*a*a+b*b*b+c*c*c){printf("%d\n",n);break;}}10摘多少個(gè)桃子。#include<>voidmain({ ints=1,i=9;for(;i>=1;i--) printf("s=%d\n",s);}Fibonacci401,1…….，前面兩個(gè)數(shù)的和。#include<>voidmain(){inti;longintf1=f2=1;for(i=1;i<=20;i++){printf("%12ld,%12ld",f1,f2);if(i%2==0)printf("\n");f1=f1+f2;f2=f2+f1;}}abc和abaac(a*100+b*10+c)*a=b*1000+a*100+a*10+c，編程求這一三位正整數(shù)#include<>voidmain(){inti,a,b,c;for(i=100;i<1000;i++){a=i/100;b=(i-a*100)/10;c=i%10;if(i*a==b*1000+a*100+a*10+c)printf("%d\n",i);}}/1000100#include<>#include<>voidmain(){ FILE*fp;int a[1000],i=0,sum=0,p,j,k;if((fp=fopen("e:\\文件2012\\","r"))==NULL){printf("不能打開文件!!!");exit(0);}while(!feof(fp)){ i++;}for(i=0;i<1000-1;i++){ p=i;for(j=i+1;j<1000;j++)if(a[p]>a[j]) p=j;if(p!=i){ k=a[i]; a[i]=a[p]; a[p]=k;}}for(i=0; i<1000; i++) printf("%4d",for(i=0; i<100; i++)sum=sum+a[i];printf("%d\n",sum);fclose(fp);}10./件中奇數(shù)的個(gè)數(shù)。#include<>#include<>voidmain(){ FILE*fp;int if((fp=fopen("e:\\文件2012\\","r"))==NULL){printf("不能打開文件!