牛客练习赛22 简单瞎搞题
思路:
bitset写dp
#pragma GCC optimize(2) #pragma GCC optimize(3) #pragma GCC optimize(4) #include<bits/stdc++.h> using namespace std; #define fi first #define se second #define pi acos(-1.0) #define LL long long //#define mp make_pair #define pb push_back #define ls rt<<1, l, m #define rs rt<<1|1, m+1, r #define ULL unsigned LL #define pll pair<LL, LL> #define pii pair<int, int> #define piii pair<pii, int> #define mem(a, b) memset(a, b, sizeof(a)) #define fio ios::sync_with_stdio(false);cin.tie(0);cout.tie(0); #define fopen freopen("in.txt", "r", stdin);freopen("out.txt", "w", stout); //head const int N = 1e6 + 5; bitset<N> dp[2]; int main() { int n, l, r; scanf("%d", &n); int now = 0; dp[now].set(0); for (int i = 0; i < n; i++) { scanf("%d %d", &l, &r); now ^= 1; dp[now].reset(); for (int j = l; j <= r; j++) { dp[now] |= dp[now^1] << (j*j); } } printf("%d\n", dp[now].count()); return 0; }