#include <stdio.h>
void f(char c[10],int *p )
{
    int max,i;
    char x[100];
    max=*p,x[0]=c[0];
    for(i=0;i<40;i++)
        if (max<*p)
        {
            max=*p;
        x[0]=c[i];
        }
        printf("%s%d\n",x[0],max);
}
void main()
{
    int a[100],i,n;
    char b[100];
    printf("the number of people(<=40)\n");
        scanf("%d\n",&n);

        printf("input the  student number and grade\n ");
    for (i=0;i<n;i++)
    {

        scanf("%s%d\n",b[i],a[i]);
   
    }

    f(b,a);

}

具体的还没细看，但这里有个比较明显的错误        scanf("%s%d\n",b[i],a[i]);
b是一个一维的字符串，楼主向单个字符串元素输入字符串明显是不行的，b应该是二维数组啊

#include <stdio.h>
#include <string.h>

void f(char c[][100],int *p,int n )
{
    int max = p[0];
    int i = 0;
    char max_name[100];
   
    strcpy(max_name, c[0]);
    for(i=0;i<n;i++)
        if (max < p[i])
        {
            max = p[i];
            strcpy(max_name,c[i]);
        }
        printf("\n\n%-8s:%d\n",max_name,max);
}
void main()
{
    int a[40];
    int i = 0;
    int n = 0;
    char b[40][100];
    printf("the number of people(<=40)\n");
        scanf("%d",&n);

        printf("input the  student number and grade\n");
    for (i=0;i<n;i++)
        scanf(" %s %d",b[i],&a[i]);

    f(b,a,n);
}