#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void getNumbers(int m,int n)
{
    int sum1[7];
    int sum2[7];
    int sum3[4];
    int sum4[4];
    srand((unsigned)time(NULL));
    if(m==35&&n==7)
    {
        for(int i=0;i<7;i++)
        {
            sum1[i] = rand()%35+1;
            for(int j=0;j<i;j++)
            {
                if(sum1[i]!=sum1[j])
                {
                    //i--;
                    sum2[i]=sum1[i];
                }
                else
                {
                    i--;
                    //sum2[i]=sum1[i];
                }
            }
            printf("%4d",sum2[i]);
        }
        printf("\n");
    }
    if(m==29&&n==7)
    {
        for(int i=0;i<7;i++)
        {
            sum1[i] = rand()%29+1;
            for(int j=0;j<i;j++)
            {
                if(sum1[i]==sum1[j])
                {
                    i--;
                }
                else
                {
                    sum2[i]=sum1[i];
                }
            }
            printf("%4d",sum2[i]);
        }
        printf("\n");
    }
    if(m==25&&n==4)
    {
        for(int i=0;i<4;i++)
        {
            sum3[i] = rand()%25+1;
            for(int j=0;j<i;j++)
            {
                if(sum3[i]==sum3[j])
                {
                    i--;
                }
                else
                {
                    sum4[i]=sum3[i];
                }
            }
            printf("%4d",sum4[i]);
        }
        printf("\n");
    }
}   
        
void main()
{
    printf("********************************\n");
    printf("乐乐彩票站现提供下列随机选号功能\n");
    printf("********************************\n");
    printf("1．35选7\n");
    printf("2．29选7\n");
    printf("3．25选4\n");
    printf("--------------\n");
    printf("请选择功能编号（1—3）：\n");
    int num;
    scanf("%d",&num);
    switch(num)
    {
    case 1 :getNumbers(35,7);break;
    case 2 :getNumbers(29,7);break;
    case 3 :getNumbers(25,4);break;
    default:printf("输入错误！");
    }
}
最后输出的数组的第一个数是-899876767678

解决方案一
sum1[i] = rand()%35+1;
两者之间的内容不起作用 删掉
 printf("%4d",sum2[i]);改为 printf("%4d",sum1[i]);

改好了，就是有点小错误：

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
void getNumbers(int m,int n)
{
    int sum1[7];
    int sum2[7];
    int sum3[4];
    int sum4[4];
    if(m==35&&n==7)
    {
        for(int i=0;i<7;i++)
        {
            sum1[i] = rand()%35+1;
            for(int j=0;j<i;j++)
            {
                if(sum1[i]!=sum1[j])
                {
                    //i--;
                    sum2[i]=sum1[i];
                }
                else
                {
                    i--;
                    //sum2[i]=sum1[i];
                }
            }
            printf("%4d",sum1[i]);
        }
        printf("\n");
    }
    if(m==29&&n==7)
    {
        for(int i=0;i<7;i++)
        {
            sum1[i] = rand()%29+1;
            for(int j=0;j<i;j++)
            {
                if(sum1[i]==sum1[j])
                {
                    i--;
                }
                else
                {
                    sum2[i]=sum1[i];
                }
            }
            printf("%4d",sum1[i]);
        }
        printf("\n");
    }
    if(m==25&&n==4)
    {
        for(int i=0;i<4;i++)
        {
            sum3[i] = rand()%25+1;
            for(int j=0;j<i;j++)
            {
                if(sum3[i]==sum3[j])
                {
                    i--;
                }
                else
                {
                    sum4[i]=sum3[i];
                }
            }
            printf("%4d",sum1[i]);
        }
        printf("\n");
    }
}   
       
void main()
{
    printf("********************************\n");
    printf("乐乐彩票站现提供下列随机选号功能\n");
    printf("********************************\n");
    printf("1．35选7\n");
    printf("2．29选7\n");
    printf("3．25选4\n");
    printf("--------------\n");
    printf("请选择功能编号（1—3）：\n");
    int num;
    scanf("%d",&num);
    switch(num)
    {
    case 1 :getNumbers(35,7);break;
    case 2 :getNumbers(29,7);break;
    case 3 :getNumbers(25,4);break;
    default:printf("输入错误！");
    }
}

谢了 ！非常感谢！

解决后就好了。