1. 程式人生 > >求1~n與x互質的數的個數(6個題、容斥原理)

求1~n與x互質的數的個數(6個題、容斥原理)

HDU 4135、POJ 2773、HDU 1695、HDU 2841、ZOJ 2836、HDU 1796

HDU 4135 Co-prime

題意: 求[l,r]x互質的數的個數
分析: 裸題
程式碼:

//
//  Created by TaoSama on 2015-10-24
//  Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio> #include <cstdlib> #include <cstring> #include <iomanip> #include <iostream> #include <map> #include <queue> #include <string> #include <set> #include <vector> using namespace std; #define pr(x) cout << #x << " = " << x << " "
#define prln(x) cout << #x << " = " << x << endl const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7; typedef long long LL; vector<int> factor; void fact(int x) { factor.clear(); for(int i = 2; i * i <= x; ++i) { if(x % i == 0) { factor.push_back(i); while
(x % i == 0) x /= i; } if(x == 1) break; } if(x > 1) factor.push_back(x); } LL calc(LL x) { LL ret = 0; //not co-prime int sz = factor.size(); for(int s = 1; s < 1 << sz; ++s) { int cnt = 0, mul = 1; for(int i = 0; i < sz; ++i) if(s >> i & 1) ++cnt, mul *= factor[i]; if(cnt & 1) ret += x / mul; else ret -= x / mul; } return x - ret; } int main() { #ifdef LOCAL freopen("C:\\Users\\TaoSama\\Desktop\\in.txt", "r", stdin); // freopen("C:\\Users\\TaoSama\\Desktop\\out.txt","w",stdout); #endif ios_base::sync_with_stdio(0); int t; scanf("%d", &t); int kase = 0; while(t--) { LL l, r, k; scanf("%I64d%I64d%I64d", &l, &r, &k); fact(k); printf("Case #%d: %I64d\n", ++kase, calc(r) - calc(l - 1)); } return 0; }

POJ 2773 Happy 2006

題意: 求第k[l,r]x互質的數
分析: 裸題上二分一下
程式碼:

//
//  Created by TaoSama on 2015-10-24
//  Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>

using namespace std;
#define pr(x) cout << #x << " = " << x << "  "
#define prln(x) cout << #x << " = " << x << endl
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;

int n, k;

typedef long long LL;

vector<int> factor;
void fact(int x) {
    factor.clear();
    for(int i = 2; i * i <= x; ++i) {
        if(x % i == 0) {
            factor.push_back(i);
            while(x % i == 0) x /= i;
        }
        if(x == 1) break;
    }
    if(x > 1) factor.push_back(x);
}

LL calc(LL x) {
    LL ret = 0;
    int sz = factor.size();
    for(int s = 1; s < 1 << sz; ++s) {
        int cnt = 0, mul = 1;
        for(int i = 0; i < sz; ++i)
            if(s >> i & 1) ++cnt, mul *= factor[i];
        if(cnt & 1) ret += x / mul;
        else ret -= x / mul;
    }
    return x - ret;
}

int main() {
#ifdef LOCAL
    freopen("C:\\Users\\TaoSama\\Desktop\\in.txt", "r", stdin);
//  freopen("C:\\Users\\TaoSama\\Desktop\\out.txt","w",stdout);
#endif
    ios_base::sync_with_stdio(0);

    while(scanf("%d%d", &n, &k) == 2) {
        fact(n);
        LL l = 1, r = 1e10;
        while(l <= r) {
            LL m = l + r >> 1;
            if(calc(m) < k) l = m + 1;
            else r = m - 1;
        }
        printf("%I64d\n", l);
    }
    return 0;
}

HDU 1695 GCD

題意: [1,l][1,r]gcd(x,y)=k
分析: kgcd(x,y)=1,x,x<y,k=0
程式碼:

//
//  Created by TaoSama on 2015-10-24
//  Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>

using namespace std;
#define pr(x) cout << #x << " = " << x << "  "
#define prln(x) cout << #x << " = " << x << endl
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;

vector<int> factor[N];
void gao() {
    bool vis[N] = {};
    for(int i = 2; i < N; ++i) {
        if(vis[i]) continue;
        for(int j = i; j < N; j += i) {
            vis[j] = true;
            factor[j].push_back(i);
        }
    }
}

typedef long long LL;

int calc(int k, int x) {
    int ret = 0;
    int sz = factor[k].size();
    for(int s = 1; s < 1 << sz; ++s) {
        int cnt = 0, mul = 1;
        for(int i = 0; i < sz; ++i) {
            if(s >> i & 1) ++cnt, mul *= factor[k][i];
        }
        if(cnt & 1) ret += x / mul;
        else ret -= x / mul;
    }
    return x - ret;
}

int main() {
#ifdef LOCAL
    freopen("C:\\Users\\TaoSama\\Desktop\\in.txt", "r", stdin);
//  freopen("C:\\Users\\TaoSama\\Desktop\\out.txt","w",stdout);
#endif
    ios_base::sync_with_stdio(0);

    int t; scanf("%d", &t);
    int kase = 0;
    gao();
    while(t--) {
        int l, r, k; scanf("%d%d%d%d%d", &l, &l, &r, &r, &k);
        if(k == 0) {printf("Case %d: 0\n", ++kase); continue;}
        l /= k, r /= k;
        if(l > r) swap(l, r);
        LL ans = 0;
        for(int i = 1; i <= l; ++i)
            ans += calc(i, r) - calc(i, i - 1);
        printf("Case %d: %I64d\n", ++kase, ans);
    }
    return 0;
}

HDU 2841 Visible Trees

題意: (0,0),(1,1)(n,m),
分析: gcd(x,y)=1,,
程式碼:

//
//  Created by TaoSama on 2015-10-24
//  Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>

using namespace std;
#define pr(x) cout << #x << " = " << x << "  "
#define prln(x) cout << #x << " = " << x << endl
const int N = 1e5 + 10, INF = 0x3f3f3f3f, MOD = 1e9 + 7;

vector<int> factor[N];
void gao() {
    bool vis[N] = {};
    for(int i = 2; i < N; ++i) {
        if(vis[i]) continue;
        for(int j = i; j < N; j += i) {
            vis[j] = true;
            factor[j].push_back(i);
        }
    }
}

int calc(int k, int x) {
    int ret = 0;
    int sz = factor[k].size();
    for(int s = 1; s < 1 << sz; ++s) {
        int cnt = 0, mul = 1;
        for(int i = 0; i < sz; ++i)
            if(s >> i & 1) ++cnt, mul *= factor[k][i];
        if(cnt & 1) ret += x / mul;
        else ret -= x / mul;
    }
    return x - ret;
}

int main() {
#ifdef LOCAL
    freopen("C:\\Users\\TaoSama\\Desktop\\in.txt", "r", stdin);
//  freopen("C:\\Users\\TaoSama\\Desktop\\out.txt","w",stdout);
#endif
    ios_base::sync_with_stdio(0);

    int t; scanf("%d", &t);
    gao();
    while(t--) {
        int n, m; scanf("%d%d", &n, &m);
        if(n > m) swap(n, m);
        long long ans = 0;
        for(int i = 1; i <= n; ++i) ans += calc(i, m);
        printf("%I64d\n", ans);
    }
    return 0;
}

ZOJ 2836 Number Puzzle

題意: [1,m]
分析: ,lcm,
程式碼:

//
//  Created by TaoSama on 2015-10-24
//  Copyright (c) 2015 TaoSama. All rights reserved.
//
//#pragma comment(linker, "/STACK:1024000000,1024000000")
#include <algorithm>
#include <cctype>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include <iostream>
#include <map>
#include <queue>
#include <string>
#include <set>
#include <vector>

using namespace std;