#include<stdio.h>
#include<stdlib.h>
int main(){
    int i, j, tra1, tra2,number=0,end;
    int a[10] = { 1, 4, 9, 11, 20, 31, 40, 51, 66 };
    printf("original arry is:\n");
        for (i = 0; i < 9; i++)
        {
        printf("%3d", a[i]);
        }
        printf("\n");
        printf("please insert a number\n");
        scanf_s("%d", &number);
        end = a[8];
        if (number>end)
        {
            a[9] = number;
        }
        else
        {
            for (i = 0; i < 9; i++)
            {
                if (a[i]>number)
                {
                    tra1 = a[i];
                    a[i] = number;
                }
                for (j = i + 1; j < 10; j++)
                {
                    tra2 = a[j];
                    a[j] = tra1;
                    tra1 = tra2;
                }
                break;
            }
        }
        for (i = 0; i < 10; i++)
        {
            printf("%3d", a[i]);
        }
        system("pause");
}

从后往前挪数字就好了

#include<stdio.h>
#include<stdlib.h>
int main(){
    int i, j, tra1, tra2,number,end;
    int a[10] = { 1, 4, 9, 11, 20, 31, 40, 51, 66 };
    printf("original arry is:\n");
        for (i = 0; i < 9; i++)
        {
        printf("%3d", a[i]);
        }
        printf("\n");
        printf("please insert a number\n");
        scanf("%d", &number);
        end = a[8];
        if (number>end)
        {
            a[9] = number;
        }
        else
         {
           for(i=0;i<10;i++)
              if(number<a[i])
                 {
                   for(j=8;j>=i;j--)
                     a[j+1]=a[j];
                     a[i]=number;
                     break;
                 }
         }
        for (i = 0; i < 10; i++)
        {
            printf("%3d ", a[i]);
        }
        system("pause");
}

从后往前 挪数字
一个O(n)的问题
别做成O(n*n)

感谢

感谢