Submission #171618

#	Time	Username	Problem	Language	Result	Execution time	Memory
171618		juggernaut	Bootfall (IZhO17_bootfall)	C++14	100 / 100	413 ms	4320 KiB

bootfall

//Just try and the idea will come!
#include<bits/stdc++.h>
#define int long long int
using namespace std;
int n,a[500],dp[250001],i,j,sum,mx=250000;
bool can[250001];
void add(int v){
    for(int j=sum;j>=0;j--)dp[j+v]+=dp[j];
    sum+=v;
}
void del(int v){
    sum-=v;
    for(int j=0;j<=sum;j++)dp[j+v]-=dp[j];
}
vector<int>ans;
main(){
    dp[0]=1;
    scanf("%lld",&n);
    for(i=0;i<n;i++){
        scanf("%lld",&a[i]);
        add(a[i]);
    }
    if(sum&1||!dp[sum/2]){
        puts("0");
        return 0;
    }
    for(i=0;i<n;i++){
        del(a[i]);
        for(j=1;j<=mx;j++)if(((sum+j)&1)||!dp[(sum+j)/2])can[j]=1;
        add(a[i]);
    }
    for(i=1;i<=mx;i++)if(!can[i])ans.push_back(i);
    printf("%lld\n",(int)ans.size());
    for(auto res:ans)printf("%lld ",res);
}

Compilation message (stderr)

bootfall.cpp:16:6: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
 main(){
      ^
bootfall.cpp: In function 'int main()':
bootfall.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld",&n);
     ~~~~~^~~~~~~~~~~
bootfall.cpp:20:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld",&a[i]);
         ~~~~~^~~~~~~~~~~~~~

• Subtask 1: 6 / 6
• Subtask 2: 7 / 7
• Subtask 3: 15 / 15
• Subtask 4: 16 / 16
• Subtask 5: 21 / 21
• Subtask 6: 35 / 35