C++统计数组中数字出现的次数

Question

一个整形数组，每个元素都是不超过两位数的正整数。编程统计该数组全部元素中数字0，1，2.。。。9个出现多少次？

Answer 1

用一个数组接收数据，使用for循环来输入数据，如果要统计某个数出现的次数并得到单数双数的个数，设置计数器，再用一个循环来遍历数组并判断。

int a[9];
int i=0,j=0,k=0
for(;i<=9;)
{
scanf("%d",&a[i++]);

}
for(;j<=9;)
{
if(a[j++]%2==1)
{

printf("odd\t");

k++;

}

else printf("even\t");

}
printf("%dodd,%deven"k,9-k);

大概就是这样了,应该没什么问题，其实主要就是一个遍历的过程，一个循环就可以了。

Answer 2

#include <cstdlib>
#include <iostream>

using namespace std;

int main(int argc, char *argv[])
{
int cnt1=0;
int cnt2=0, cnt3=0, cnt4=0, cnt5=0, cnt6=0, cnt7=0, cnt8=0, cnt9=0, cnt0=0;
int c[30]={1, 2, 3, 4, 5, 4, 3, 3, 5, 2, 6, 2, 4, 3, 5, 4, 2, 1, 7, 1};
for(int i=0;i<20;i++)
{
switch(c[i]){
case 1:
++cnt1;
break;
case 2:
++cnt2;
break;
case 3:
++cnt3;
break;
case 4:
++cnt4;
break;
case 5:
++cnt5;
break;
case 6:
++cnt6;
break;
case 7:
++cnt7;
break;
case 8:
++cnt8;
break;
case 9:
++cnt9;
break;
case 0:
++cnt0;
break;

}
}
cout << "1出现的次数：" << cnt1 << endl ;
cout << "2出现的次数：" << cnt2 << endl ;
cout << "3出现的次数：" << cnt3 << endl;
cout << "4出现的次数：" << cnt4 << endl ;
cout << "5出现的次数：" << cnt5 << endl ;
cout << "6出现的次数：" << cnt6 << endl ;
cout << "7出现的次数：" << cnt7 << endl ;
cout << "8出现的次数：" << cnt8 << endl ;
cout << "9出现的次数：" << cnt9 << endl ;
cout << "0出现的次数：" << cnt0 << endl;

system("PAUSE");
return EXIT_SUCCESS;
}

Answer 3

#include<iostream>

using namespace std;

int main()
{
int data[] = {1,1,1,1,1,1,2,2,3,3,4,4,5,6,7,7,8,8,9,9,9,0} ;// 原本的数组
int one = 0,
two =0,
three = 0,
four = 0,
five = 0,
six = 0,
seven = 0,
eight = 0,
nine = 0,
zero = 0;
int i = sizeof data/sizeof data[0];
while(i>=0)
switch(data[i--])
{
case 1:
one++;
break;
case 2:
two++;
break;
case 3:
three++;
break;
case 4:
four++;
break;
case 5:
five++;
break;
case 6:
six++;
break;
case 7:
seven++;
break;
case 8:
eight++;
break;
case 9:
nine++;
break;
case 0:
zero++;break;
default:
break;
}
cout<<"\none="<<one
<<"\ntwo="<<two
<<"\nthree="<<three
<<"\nfour="<<four
<<"\nfive="<<five
<<"\nsix="<<six
<<"\nseven="<<seven
<<"\neight="<<eight
<<"\nnine="<<nine
<<"\nzero="<<zero;
return 0;

}

Answer 4

int a[100];//假设为已知整型数组
int b[100];//用来存储统计结果
for(int i=0;i<100;i++)
b[i]=0;
for(i=0; i<100; i++)
{
b[a[i]]++;
}

Answer 5

作业自己做吧