麻烦大佬指出为啥输出乱码

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

struct shot
{
    char id[4];
    int x;
    int y;
};
int main(void)
{

    struct shot people[10000];
    float max=0,min=0;
    char *maxindex=NULL,*minindex=NULL;

    int num;
    scanf("%d",&num);

    for(int i=0;i<num;i++)
    {
        scanf("%s %d %d",people[i].id,&people[i].x,&people[i].y);
        float score = sqrt(people[i].y*people[i].y+people[i].x*people[i].x);
        if(i==0)
        {
            min = score;
            minindex =people[i].id;
        }
        if((float)score>max)
        {
            max = score;
            maxindex = people[i].id;
        }
        if(score<=min)
        {
            min = score;
            minindex = people[i].id;
        }
        

    }

    printf("%s %s\n",minindex,maxindex);

    system("pause");
    return 0;

}