简单瞎搞题 - 牛客

PS：怎么没想到用bitset优化，orz。

#include<bits/stdc++.h>
#include<bitset>
#define ll long long
#define P pair<int, int>
#define PP pair<int,pair<int, int>>
#define pb push_back
#define pp pop_back
#define lson root << 1
#define INF (int)2e9 + 7
#define rson root << 1 | 1
#define LINF (unsigned long long int)1e18
#define mem(arry, in) memset(arry, in, sizeof(arry))
using namespace std;

int n;
bitset<1000005> dp[2];

int main()
{
    cin >> n;
    dp[0][0] = 1;
    int now = 0, l, r;
    for(int i = 1; i <= n; i++) {
        cin >> l >> r;
        for(int j = l; j <= r; j++) dp[now ^ 1] |= dp[now] << (j * j);
        dp[now].reset();
        now ^= 1;
    }
    cout << dp[now].count() << endl;
    return 0;
}