Submission #1846747

---

Source Code Expand

#include <bits/stdc++.h>
#ifdef DEMETRIO
#define deb(...) fprintf(stderr,__VA_ARGS__)
#define deb1(x) cerr << #x << " = " << x << endl
#else
#define deb(...) 0
#define deb1(x) 0
#endif
#define pb push_back
#define mp make_pair
#define fst first
#define snd second
#define fore(i,a,b) for(int i=a,ThxDem=b;i<ThxDem;++i)
#define SZ(x) ((int)x.size())
using namespace std;
typedef long long ll;

int n,m,r;
int q[100005],w[100005],z[100005];

int main(){
	scanf("%d%d",&n,&m);
	fore(i,0,n){
		int x;
		scanf("%d",&x);
		q[x]++;
		w[x%m]++;
	}
	fore(i,0,m){
		int j=(m-i)%m;
		if(i>j)break;
		if(i==j){
			r+=w[i]/2;
			z[i]=w[i]%2;
		}
		else {
			int k=min(w[i],w[j]);
			r+=k;z[i]=w[i]-k;z[j]=w[j]-k;
		}
	}
	fore(i,1,100005){
		int k=min(q[i],z[i%m])/2;
		r+=k;
		z[i%m]-=2*k;
	}
	printf("%d\n",r);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:22:21: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d",&n,&m);
                     ^
./Main.cpp:25:17: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d",&x);
                 ^

Judge Result