soj 3137 Simple Computing 容斥原理 hdu 1796 How many integers can you find

/*
 * hdu1796.c
 *
 *  Created on: 2011-10-3
 *      Author: bjfuwangzhu
 */
#include<stdio.h>
#define LL long long
#define nmax 11
int num[nmax], nlen;
LL res;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
void dfs(int start, int c, int lcm, int n) {
    int i;
    lcm = lcm / gcd(lcm, num[start]) * num[start];
    if (c & 1) {
        res += n / lcm;
    } else {
        res -= n / lcm;
    }
    for (i = start + 1; i < nlen; i++) {
        dfs(i, c + 1, lcm, n);
    }
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int n, m, mm, i, j;
    while (~scanf("%d %d", &n, &m)) {
        for (i = 0, nlen = 0; i < m; i++) {
            scanf("%d", &mm);
            if (mm > 0 && mm < n) {
                num[nlen++] = mm;
            }
        }
        res = 0;
        for (j = 0; j < nlen; j++) {
            dfs(j, 1, num[j], n - 1);
        }
        printf("%lld\n", res);
    }
    return 0;
}

 

/*
 * soj3137.c
 *
 *  Created on: 2011-10-10
 *      Author: bjfuwangzhu
 */

#include<stdio.h>
#define LL long long
#define nmax 11
int num[nmax];
int n, m, res, flag;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
void dfs(int start, int lcm) {
    LL temp;
    if (start == n) {
        if (flag & 1) {
            res += m / lcm;
        } else if (flag > 0) {
            res -= m / lcm;
        }
        return;
    }
    temp = (LL) lcm;
    temp = temp / gcd(lcm, num[start]) * num[start];
    flag++;
    if (temp <= m) {
        dfs(start + 1, temp);
    }
    flag--;
    dfs(start + 1, lcm);
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int t, i;
    scanf("%d", &t);
    while (t--) {
        scanf("%d %d", &n, &m);
        for (i = 0; i < n; i++) {
            scanf("%d", num + i);
        }
        res = 0, flag = 0;
        dfs(0, 1);
        printf("%d\n", res);
    }
    return 0;
}

/*
 * soj3137.c
 *
 *  Created on: 2011-10-10
 *      Author: bjfuwangzhu
 */

#include<stdio.h>
#define LL long long
#define nmax 11
int num[nmax];
int n, m, res;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
void dfs(int i, LL lcm, int flag) {
    int j;
    lcm = lcm / gcd(lcm, num[i]) * num[i];
    if (flag & 1) {
        res += m / lcm;
    } else {
        res -= m / lcm;
    }
    flag++;
    for (j = i + 1; j < n; j++) {
        dfs(j, lcm, flag);
    }
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int t, i;
    scanf("%d", &t);
    while (t--) {
        scanf("%d %d", &n, &m);
        for (i = 0; i < n; i++) {
            scanf("%d", num + i);
        }
        res = 0;
        for (i = 0; i < n; i++) {
            dfs(i, 1, 1);
        }
        printf("%d\n", res);
    }
    return 0;
}

hdu 1796 How many integers can you find

/*
 * hdu1796.c
 *
 *  Created on: 2011-10-3
 *      Author: bjfuwangzhu
 */
#include<stdio.h>
#define LL long long
#define nmax 11
int num[nmax], nlen, flag;
LL res;
int gcd(int a, int b) {
    return b == 0 ? a : gcd(b, a % b);
}
void dfs(int start, int lcm, int n) {
    LL temp;
    if (start == nlen) {
        if (flag & 1) {
            res += n / lcm;
        } else if (flag > 0) {
            res -= n / lcm;
        }
        return;
    }
    temp = (LL) lcm;
    temp = temp / gcd(lcm, num[start]) * num[start];
    flag++;
    if (temp <= n) {
        dfs(start + 1, temp, n);
    }
    flag--;
    dfs(start + 1, lcm, n);
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int n, m, mm, i;
    while (~scanf("%d %d", &n, &m)) {
        for (i = 0, nlen = 0; i < m; i++) {
            scanf("%d", &mm);
            if (mm > 0 && mm < n) {
                num[nlen++] = mm;
            }
        }
        res = 0, flag = 0;
        dfs(0, 1, n - 1);
        printf("%lld\n", res);
    }
    return 0;
}