Submission #386861

#	Time	Username	Problem	Language	Result	Execution time	Memory
386861		vanic	Gift (IZhO18_nicegift)	C++14	30 / 100	2080 ms	123472 KiB

nicegift

#include <cstdio>
#include <cmath>
#include <algorithm>
#include <set>
 
using namespace std;
typedef long long ll;
 
const int maxn=1e6+5;
 
ll a[maxn];
int ind[maxn];
ll sum;
pair < ll, int > v[maxn*3];
set < int > cur;

bool cmp(int a1, int b1){
	return a[a1]>a[b1];
}

int main(){
	int n, k;
	scanf("%d%d", &n, &k);
	for(int i=0; i<n; ++i){
		scanf("%lld", a+i);
		sum+=a[i];
		ind[i]=i;
	}
	if(sum%k){
		printf("-1\n");
		return 0;
	}
	sum/=k;
	for(int i=0; i<n; ++i){
		if(a[i]>sum){
			printf("-1\n");
			return 0;
		}
	}
	sort(ind, ind+n, cmp);
	int pos=0;
	int iduc;
	int br=0;
	for(int i=0; i<n; ++i){
		iduc=pos+a[ind[i]];
		if(iduc>sum){
			v[br]={pos, ind[i]+1};
			++br;
			iduc-=sum;
			pos=0;
		}
		v[br]={pos, ind[i]+1};
		++br;
		if(iduc!=sum){
			v[br]={iduc, -ind[i]-1};
			++br;
		}
		else{
			iduc=0;
		}
		pos=iduc;
	}
	v[br]={sum, 0};
	++br;
	sort(v, v+br);
	int sol=0;
	for(int i=0; i<br-1; ++i){
		if(v[i].first!=v[i+1].first){
			++sol;
		}
	}
	printf("%d\n", sol);
	for(int i=0; i<br-1; ++i){
		if(v[i].second>0){
			cur.insert(v[i].second);
		}
		else{
			cur.erase(-v[i].second);
		}
		if(v[i].first==v[i+1].first){
			continue;
		}
		printf("%lld ", v[i+1].first-v[i].first);
		for(int x : cur){
			printf("%d ", x);
		}
		printf("\n");
	}
	return 0;
}

Compilation message (stderr)

nicegift.cpp: In function 'int main()':
nicegift.cpp:23:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   23 |  scanf("%d%d", &n, &k);
      |  ~~~~~^~~~~~~~~~~~~~~~
nicegift.cpp:25:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   25 |   scanf("%lld", a+i);
      |   ~~~~~^~~~~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 12 / 12
• Subtask 4: 0 / 19
• Subtask 5: 0 / 51