文档介绍：六、,统计在所输入的50个实数中有多少个正数、多少个负数、多少个零。#include""#defineN50voidmain(){floatx;unsignedints1,s2,s3,i;s1=s2=s3=0;for(i=1;i<=N;i++){scanf("%f",&x);if(x<0)s1++;elseif(x==0)s2++;elses3++;}printf("负数%u个,零%u个,正数%u个\n",s1,s2,s3);} ,计算并输出方程X2+Y2=1989的所有整数解。#include""voidmain(){intx,y;for(x=-45;x<=45;x++){y=-45;while(y<=45){if(x*x+y*y==1989)printf("%d*%d+%d*%d=%d\n",x,x,y,y,1989);y++;}}} ,输入一个10进制正整数,然后输出它所对应的八进制、十六进制数。#include""voidmain(){unsignedintx;printf("请输入一个十进制正整数:");scanf("%u",&x);printf("%d=八进制数%o=十六进制数%x\n",x,x,x);} ,找出1000以内的所有完数,并输出其因子。#include""voidmain(){inti,j,s=1;for(i=1;i<=1000;i++,s=1){for(j=2;j<=i/2;j++)if(i%j==0)s+=j;//求i的因子和if(s==i){printf("%d=1",i);//如果i是完数则输出其各因子for(j=2;j<=i/2;j++)if(i%j==0)printf("+%d",j);printf("\n");}}} ,输出它的所有质数因子。#include""voidmain(){intm,i=2;printf("请输入一个整数:");scanf("%d",&m);while(m!=1)if(m%i==0){printf("%d",i);m/=i;}elsei++;printf("\n");} ,输出其中能被数组中其它元素整除的那些数组元素。#include""#defineN20voidmain(){inta[N],i,j;for(i=0;i<N;i++)scanf("%d",&a[i]);for(i=0;i<N;i++)for(j=0;j<N;j++)if(a[i]%a[j]==0&&i!=j){printf("%d\n",a[i]);break;}} (数组元素个数自定),输出在两个数组中都出现的元素。#include""#defineNA6#defineNB8voidmain(){floata[NA],b[NB];inti,j;for(i=0;i<NA;i++)scanf("%f",&a[i]);for(i=0;i<NB;i++)scanf("%f",&b[i]);for(i=0;i<NA;i++)for(j=0;j<NB;j++)if(a[i]==b[j]){printf("%f\n",a[i]);break;}} (数组元素个数自定),输出在两个数组中都不出现的元素。#include""#defineNA6#defineNB8voidmain(){floata[NA],b[NB];inti,j;for(i=0;i<NA;i++)scanf("%f",&a[i]);for(i=0;i<NB;i++)scanf("%f",&b[i]);for(i=0;i<NA;i++){for(j=0;j<NB;j++)if(a[i]==b[j])break;if(j==NB)printf("%f",a[i]);}printf("\n");for(i=0;i<NB;i++){for(j=0;j<NA;j++)if(b[i]==a[j])break;if(j==NA)printf("%f",b[i]);}printf("\n");} ,将字符数组S2中的全部字符拷贝到字符数组S1中。#include""voidmain(){chars1[20],s2[]="Goodmorning!";inti=0;while((s1[i++]=s2[i])!='\0');printf("%s\n",s1);} ,判别该年份是否闰年(定义一个宏以判别该年份是否闰年)。#include<>#definef(year)year%4==0&