#include <bits/stdc++.h> using namespace std; #define st first #define nd second #define pb push_back #define sz(x) (int)(x).size() #define ll long long ll mod=1000000007; int inf=1000000007; ll infl=1000000000000000007; ll DP[5007]; ll a[5007]; ll pot[5007]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); pot[0]=1; for(int i=1;i<=5000;i++) pot[i]=pot[i-1]*2%mod; int n; cin>>n; for(int i=1;i<=n;i++) cin>>a[i]; sort(a+1,a+1+n); DP[0]=1; ll ans=0; for(int i=1;i<=n;i++) { for(int j=4998;j>=a[i]-1;j--) { if(j+a[i]>4998) ans=(ans+DP[j]*pot[n-i])%mod; else DP[j+a[i]]=(DP[j+a[i]]+DP[j])%mod; } } for(int i=1;i<=4998;i++) ans=(ans+DP[i])%mod; cout<<ans; return 0; }
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 | #include <bits/stdc++.h> using namespace std; #define st first #define nd second #define pb push_back #define sz(x) (int)(x).size() #define ll long long ll mod=1000000007; int inf=1000000007; ll infl=1000000000000000007; ll DP[5007]; ll a[5007]; ll pot[5007]; int main() { ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0); pot[0]=1; for(int i=1;i<=5000;i++) pot[i]=pot[i-1]*2%mod; int n; cin>>n; for(int i=1;i<=n;i++) cin>>a[i]; sort(a+1,a+1+n); DP[0]=1; ll ans=0; for(int i=1;i<=n;i++) { for(int j=4998;j>=a[i]-1;j--) { if(j+a[i]>4998) ans=(ans+DP[j]*pot[n-i])%mod; else DP[j+a[i]]=(DP[j+a[i]]+DP[j])%mod; } } for(int i=1;i<=4998;i++) ans=(ans+DP[i])%mod; cout<<ans; return 0; } |