#include <bits/stdc++.h> using namespace std; #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) #define REP(i, n) for(int i = 0; i < (n); ++i) #define ff first #define ss second using ll = long long; using pii = pair<int, int>; template<class T> int size(T && a) { return (int)(a.size()); } ostream& operator << (ostream &os, string str) { for(char c : str) os << c; return os; } template <class A, class B> ostream& operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.ff << "," << p.ss << ')'; } template <class T> auto operator << (ostream &os, T &&x) -> decltype(x.begin(), os) { os << '{'; for(auto it = x.begin(); it != x.end(); ++it) os << *it << (it == prev(x.end()) ? "" : " "); return os << '}'; } template <class T> ostream& operator << (ostream &os, vector<vector<T>> vec) { for(auto x : vec) os << "\n " << x; return os; } void dump() {} template <class T, class... Args> void dump(T &&x, Args... args) { cerr << x << "; "; dump(args...); } #ifdef DEBUG # define debug(x...) cerr << "[" #x "]: ", dump(x), cerr << '\n' #else # define debug(...) 0 #endif //-------------------------------------------------- const int MOD = int(1e9) + 7; int add(int a, int b) { if(a+b >= MOD) return a+b-MOD; return a+b; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); int n; cin >> n; vector<int> a(n); int sum = 0; REP(i, n) { cin >> a[i]; sum += a[i]; } sort(a.begin(), a.end()); vector<int> dp(sum+1), prev_dp(sum+1); dp[0] = prev_dp[0] = 1; int temp = 0; REP(i, n) { FOR(k, a[i]-1, temp) { dp[k+a[i]] = add(dp[k+a[i]], prev_dp[k]); } temp += a[i]; prev_dp = dp; debug(dp); } int ans = 0; FOR(k, 1, sum) ans = add(ans, dp[k]); cout << ans << '\n'; }
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 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 | #include <bits/stdc++.h> using namespace std; #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) #define REP(i, n) for(int i = 0; i < (n); ++i) #define ff first #define ss second using ll = long long; using pii = pair<int, int>; template<class T> int size(T && a) { return (int)(a.size()); } ostream& operator << (ostream &os, string str) { for(char c : str) os << c; return os; } template <class A, class B> ostream& operator << (ostream &os, const pair<A, B> &p) { return os << '(' << p.ff << "," << p.ss << ')'; } template <class T> auto operator << (ostream &os, T &&x) -> decltype(x.begin(), os) { os << '{'; for(auto it = x.begin(); it != x.end(); ++it) os << *it << (it == prev(x.end()) ? "" : " "); return os << '}'; } template <class T> ostream& operator << (ostream &os, vector<vector<T>> vec) { for(auto x : vec) os << "\n " << x; return os; } void dump() {} template <class T, class... Args> void dump(T &&x, Args... args) { cerr << x << "; "; dump(args...); } #ifdef DEBUG # define debug(x...) cerr << "[" #x "]: ", dump(x), cerr << '\n' #else # define debug(...) 0 #endif //-------------------------------------------------- const int MOD = int(1e9) + 7; int add(int a, int b) { if(a+b >= MOD) return a+b-MOD; return a+b; } int main() { ios_base::sync_with_stdio(0); cin.tie(0); int n; cin >> n; vector<int> a(n); int sum = 0; REP(i, n) { cin >> a[i]; sum += a[i]; } sort(a.begin(), a.end()); vector<int> dp(sum+1), prev_dp(sum+1); dp[0] = prev_dp[0] = 1; int temp = 0; REP(i, n) { FOR(k, a[i]-1, temp) { dp[k+a[i]] = add(dp[k+a[i]], prev_dp[k]); } temp += a[i]; prev_dp = dp; debug(dp); } int ans = 0; FOR(k, 1, sum) ans = add(ans, dp[k]); cout << ans << '\n'; } |