Submission #3911799

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Source Code Expand

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

#define MIN(a,b) ((a)<(b)?(a):(b))

int cmp(const void *a,const void *b){
  return *(int *)a-*(int *)b;
}

void run(void){
  int n,m;
  scanf("%d%d",&n,&m);
  int *x=(int *)calloc(n,sizeof(int));
  int i;
  for(i=0;i<n;i++) scanf("%d",x+i);
  int *cnt=(int *)calloc(m,sizeof(int));
  for(i=0;i<n;i++) if(x[i]) cnt[x[i]%m]++;
  int ans=cnt[0]/2;
  cnt[0]%=2;
  for(i=1;i<m-i;i++){
    int k=MIN(cnt[i],cnt[m-i]);
    ans+=k;
    cnt[i]-=k;
    cnt[m-i]-=k;
  }
  if(m%2==0){
    ans+=cnt[m/2]/2;
    cnt[m/2]%=2;
  }
  qsort(x,n,sizeof(int),cmp);
  i=0;
  while(i+1<n){
    if(x[i]==x[i+1] && cnt[x[i]%m]>=2){
      ans++;
      cnt[x[i]%m]-=2;
      i+=2;
    } else {
      i++;
    }
  }
  printf("%d\n",ans);
}

int main(void){
  run();
  return 0;
}

Submission Info

Compile Error

./Main.c: In function ‘run’:
./Main.c:12:3: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&n,&m);
   ^
./Main.c:15:20: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result]
   for(i=0;i<n;i++) scanf("%d",x+i);
                    ^

Judge Result