Help me in solving ABSTRING problem

help
,
1

My issue

My code

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


int main() {
    int t;
    scanf("%d",&t);
    for (int i=0;i<t;i++){
        int n;
        scanf("%d",&n);
        char str[n+1];
      fgets(str,sizeof(str),stdin);
        getchar();
        str[strcspn(str,"\n")]='\0';
        int count[256]={0};
        for(int i=0;str[i]!='\0';i++){
            count[(int)str[i]]++;
            
        } 
        
        
         int flag =0;
        for (int i=0;i<256;i++){
            if(count[i]!=0){
              if((count[i])%2==0){
                flag=1;
              }else{
                flag=0;
            }
        }
        }
     
        if(flag==1){
            printf("NO\n");
        }else{
            printf("YES\n");
        }
        
    }
    
    return 0;
    
    
    
    
}

Problem Link: String Game Practice Coding Problem