10.11 NOIP模拟题(1)

/*
离散化
差分
*/
#include<bits/stdc++.h>

#define N 4000007

using namespace std;
int n,ans;
int tmp[N],a[N],b[N],s[N];

int main()
{
    freopen("meizi.in","r",stdin);
    freopen("meizi.out","w",stdout);
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
    {
        scanf("%d%d",&a[i],&b[i]);
        tmp[(i<<1)-1]=a[i],tmp[i<<1]=b[i];
    }
    int num=(n<<1)+1;
    sort(tmp+1,tmp+num);
    for(int i=1;i<=n;i++)
    {
        a[i]=lower_bound(tmp+1,tmp+num,a[i])-tmp;
        b[i]=lower_bound(tmp+1,tmp+num,b[i])-tmp;
        s[a[i]]++;s[b[i]+1]--; 
    }
    for(int i=1;i<=num;i++) s[i]+=s[i-1];
    for(int i=1;i<=num;i++) ans=max(ans,s[i]);
    printf("%d\n",ans);
    return 0;
}

/*
容斥原理 先保证每列满足
答案为 全部(每列满足) - 一行白(每列满足) + 两行白(每列满足)...
ans=(-1)^k*C(n,k)*(2^(n-k)-1)^m
阶乘逆元组合数
*/
#include<iostream>
#include<cstdio>
#include<cstring>

#define N 200001
#define M 1000000007
#define ll long long

using namespace std;
ll fac[N]={1,1},inv[N]={1,1},f[N]={1,1};
int n,m;
ll ans;

ll ksm(ll a,ll b)
{
    ll res=1;
    while(b)
    {
        if(b&1) res=res*a%M;
        b>>=1;a=a*a%M;
    }return res%M;
}

ll C(ll a,ll b)
{
    return (fac[a]*inv[b]%M*inv[a-b]%M)%M;
}

int main()
{
    freopen("matrix.in","r",stdin);
    freopen("matrix.out","w",stdout);
    for(int i=2;i<N;i++)
    {
        fac[i]=fac[i-1]*i%M;
        f[i]=(M-M/i)*f[M%i]%M;
        inv[i]=inv[i-1]*f[i]%M;
    }
    
    scanf("%d%d",&n,&m);
    for(int k=0;k<=n;k++)
    {
        if(k&1)
          ans=(ans-C(n,k)%M*ksm(ksm(2,n-k)-1,m))%M;
        else
          ans=(ans+C(n,k)%M*ksm(ksm(2,n-k)-1,m))%M;
    }
    printf("%lld\n",(ans+M)%M);
    return 0;
}

/*
和的期望即期望的和
55分暴力就行

线段树区间乘,加,求和
*/
#include <iostream>
#include <cstring>
#include <cmath>
#include <cstdio>
#include <algorithm>
#include <queue>
#include <vector>
#include <map>
#include <complex>

#define inf 0x3f3f3f3f
#define eps 1e-10

#define lc k << 1
#define rc k << 1 | 1

using namespace std;

typedef long long ll;
typedef pair<ll, int> P;
ll p;
double tmp[200005];

struct node{
    double dat, tag1, tag2;
    int l, r;
};

struct seg{
    node d[800005];
    
    void pushup(int k){
        d[k].dat = d[lc].dat + d[rc].dat;
    }
    
    void build(int k, int l, int r){
        d[k].l = l; d[k].r = r; d[k].tag1 = 0; d[k].tag2 = 1;
        if(l == r){
            d[k].dat = tmp[l];
            return;
        }
        int mid = (l + r) >> 1;
        build(lc, l, mid);
        build(rc, mid + 1, r);
        pushup(k);
    }
    
    void add(int k, double x){
        double len = d[k].r - d[k].l + 1;
        d[k].dat = (d[k].dat + x * len);
        d[k].tag1 = (d[k].tag1 + x);
    }
    
    void mul(int k, double x){
        d[k].dat = d[k].dat * x;
        d[k].tag1 = d[k].tag1 * x;
        d[k].tag2 = d[k].tag2 * x;
    }
    
    void pushdown(int k){
        if(fabs(d[k].tag2 - 1) > eps){
            mul(lc, d[k].tag2);
            mul(rc, d[k].tag2);
            d[k].tag2 = 1;
        }
        if(fabs(d[k].tag1) > eps){
            add(lc, d[k].tag1);
            add(rc, d[k].tag1);
            d[k].tag1 = 0;
        }
    }
    
    void add(int k, int l, int r, double x){
        if(l <= d[k].l && d[k].r <= r){
            add(k, x); return;
        }
        pushdown(k);
        int mid = (d[k].l + d[k].r) >> 1;
        if(l <= mid) add(lc, l, r, x);
        if(r > mid) add(rc, l, r, x);
        pushup(k);
    }
    
    void mul(int k, int l, int r, double x){
        if(l <= d[k].l && d[k].r <= r){
            mul(k, x); return;
        }
        pushdown(k);
        int mid = (d[k].l + d[k].r) >> 1;
        if(l <= mid) mul(lc, l, r, x);
        if(r > mid) mul(rc, l, r, x);
        pushup(k);
    }
    
    double query(int k, int l, int r){
        if(l <= d[k].l && d[k].r <= r){
            return d[k].dat;
        }
        pushdown(k); double sum = 0;
        int mid = (d[k].l + d[k].r) >> 1;
        if(l <= mid) sum = (sum + query(lc, l, r));
        if(r > mid) sum = (sum + query(rc, l, r));
        return sum;
    }
    
}Seg;

int n, m;

int main(){
        
    freopen("random.in", "r", stdin);
    freopen("random.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(int i = 1; i <= n; i ++) scanf("%lf", &tmp[i]);
    Seg.build(1, 1, n);
    while(m--){
        int opt, l1, r1, l2, r2; ll x;
        scanf("%d", &opt);
        if(opt == 1){
            scanf("%d%d%d%d", &l1, &r1, &l2, &r2);
               double d1 = Seg.query(1, l1, r1);
             double d2 = Seg.query(1, l2, r2);
               Seg.mul(1, l1, r1, double(r1 - l1) / double(r1 - l1 + 1));
             Seg.mul(1, l2, r2, double(r2 - l2) / double(r2 - l2 + 1));
            Seg.add(1, l1, r1, d2 / double(r1 - l1 + 1) / double(r2 - l2 + 1));
             Seg.add(1, l2, r2, d1 / double(r2 - l2 + 1) / double(r1 - l1 + 1));                   
        }
        if(opt == 2){
            scanf("%d%d", &l1, &r1);
            printf("%.8lf\n", Seg.query(1, l1, r1));
        }
    }
    return 0;
}

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转载自www.cnblogs.com/L-Memory/p/9771505.html