#include<stdio.h>intmain(void){char c;int letters =0,space =0,digit =0,others =0;printf("please input some characters\n");while((c =getchar())!='\n'){if(c>='a'&&c<='z'||c>='A'&&c<='Z'){
letters++;}elseif(c==' '){
space++;}elseif(c<='9'&&c>='0'){
digit++;}else{
others++;}}printf("letters is %d,space is %d,digit is %d,others is %d",letters,space,digit,others);return0;}
2一千以内的的所有完数
#include<stdio.h>//找到1000以内的所有完数,要找到每一个数的因子;如果一个数是素数,那么它就不可能是完数intmain(void){int i,j;for(i=1;i<=1000;i++){int sum =0;for(j=1;j<i;j++){if(i%j==0){
sum = sum + j;//printf("%d\t",sum);}else{continue;}}if(i==sum){printf("%d\t",i);}else{continue;}}return0;}
3自由落体运动
#include<stdio.h>intmain(void){float i,j =100,sum =0;for(i=1;i<=10;i++){
j = j/2;
sum = sum + j;}printf("%f\t%f",sum,j);return0;}
4乒乓球比赛
#include<stdio.h>//i代表a的对手,j代表b的对手,k代表c的对手intmain(void){char i,j,k;for(i='x';i<='z';i++){for(j='x';j<='z';j++){if(i!=j){for(k='x';k<='z';k++){if(k!=i&&k!=j){if(i!='x'&&k!='x'&&k!='z'){printf("order is a--%c\tb==%c\tc--%c",i,j,k);}}}}}}return0;}
5如何用分数表示c语言?
#include<stdio.h>intmain(void){float melocuar[20],denominator[20];
melocuar[0]=2;
melocuar[1]=3;
denominator[0]=1;
denominator[1]=2;int i,j;float sum =0;for(i=2;i<=19;i++){
melocuar[i]= melocuar[i-1]+melocuar[i-2];
denominator[i]= denominator[i-1]+denominator[i-2];}for(j=0;j<=19;j++){
sum = sum + melocuar[j]/denominator[j];printf("%f\t",melocuar[j]/denominator[j]);}printf("%f",sum);return0;}