42-2017蓝桥杯b java

#include <iostream>
#include <algorithm>
using namespace std;

int main(){
    int n, m;
   	int a[15];
   	for(int i = 0; i < 9; i++){
   		a[i] = i + 1;
   	}
   	int cnt = 0; 
   	
   	do{
   		int c1 = a[0] + a[1] + a[2] + a[3];
   		int c2 = a[3] + a[4] + a[5] + a[6];
   		int c3 = a[6] + a[7] + a[8] + a[0];
   		if(c1 == c2 && c2 == c3)
   			cnt++;
//   		cout << a[0] << "," << a[1] << "," << a[2] << endl;
   	}while(next_permutation(a, a + 9));
	cout << "cnt: " << cnt << endl;
	
/*
全排列库函数： 
next_permutation: 
	1.必须是有序的从小大排好序的才行； 
	2.参数：数组名，数组名+排序的长度 

*/
    
    return 0;
}

import java.util.Scanner;

public class Main {
	public static int[] visit = new int[10];
	public static int[] a = new int[10];
	public static int n;
	public static int all = 0;
	public static int ys = 0;
	
	public static void main(String[] args) {
		 Scanner cin = new Scanner(System.in);
		 n = cin.nextInt();
//		 long ans = 1;
//		 for(int i = 1; i <= 9; i++) { //九的全排列：362880
//			 ans *= i;
//		 }
//		 System.out.println(ans);
		 dfs(0);
		 System.out.println(all);  //362880
		 System.out.println(ys / 6);
		 
	}
	public static void dfs(int cnt) {
		if(cnt == n) {
			all++;
			//打印所有全排列
//			for(int i = 0; i < n; i++) {
////				System.out.print(box[i]);
//				System.out.printf("%5d", box[i]);
//			}
//			System.out.println();
			//判断是否和要求
			int x = a[0] + a[1] + a[2] + a[3];
			int x1 = a[3] + a[4] + a[5] + a[6];
			int x2 = a[6] + a[7] + a[8] + a[0];
			if(x == x1 && x == x2) {
//				System.out.println();
				ys++;
			}
			return ;
		}
		for(int i = 1; i <= n; i++) {
			if(visit[i] == 0) {
				a[cnt] = i;
				visit[i] = 1;
				dfs(cnt + 1);
				visit[i] = 0;
			}
		}
	}
}

import java.util.Arrays;
import java.util.Scanner;

public class Main {
	public static int[] visit = new int[10];
	public static int n;
	public static double[][] a = new double[40][40];
	
	public static void main(String[] args) {
		 Scanner cin = new Scanner(System.in);
//		 n = cin.nextInt();
		 n = 29;
		 for(int i = 1; i <= n; i++) {
			 for(int j = 1; j <= i; j++) {
				 long x = cin.nextLong();
				 a[i][j] += x;
				 a[i+1][j] +=  a[i][j] / 2.0;  
				 a[i+1][j+1] += a[i][j] / 2.0;  
			 }
		 }
		 //打印处理后的数据，验证前几个看是否符合预期
		 for(int i = 1; i <= n + 1; i++) {
			 for(int j = 1; j <= i; j++) {
				 System.out.print(a[i][j] + " ");
			 }
			 System.out.println();
		 }
		 System.out.println("============");
		 
		 //自己寻找最大最小值：
			 double min = 0x3f3f3f * 1.0;
			 double max = -1;
			 for(int i = 1; i <= 30; i++) {
				 if(a[30][i] > max) max = a[30][i];
				 if(a[30][i] < min) min = a[30][i];
			 }
			 System.out.println("min" + min + "; man " + max);
			 
		 //用函数排序找最大最小值：
		 Arrays.sort(a[30]);
		 for(int i = 0; i < 40; i++) {
			 System.out.print(a[30][i] + " ");
		 }
		 System.out.println();
		 
		 System.out.println("min" + a[30][10] + "; man " + a[30][39]);
		 double ans = (a[30][39] / a[30][10]) * 2086458231;
		 System.out.println(ans);
		 System.out.println((long)ans);
		 
//		 7.2665192664E10
//		 72665192664  
	}
}

public class Main
{
    static int len(int x){
        if(x<10) return 1;
        return len(x/10)+1;
    }


    // 取x的第k位数字
    static int f(int x, int k){
        if(len(x)-k==0)
        return x%10;
        return __________;  //填空
    }


    public static void main(String[] args)
    {
        int x = 23513;
        //System.out.println(len(x));
        System.out.println(f(x,3));
    }
}

/*
6.最大公共子串

最大公共子串长度问题就是：
求两个串的所有子串中能够匹配上的最大长度是多少。

比如："abcdkkk" 和 "baabcdadabc"，
可以找到的最长的公共子串是"abcd",所以最大公共子串长度为4。

下面的程序是采用矩阵法进行求解的，这对串的规模不大的情况还是比较有效的解法。
*/
public class Main
{
	static int f(String s1, String s2)
	{
		char[] c1 = s1.toCharArray();
		char[] c2 = s2.toCharArray();

		int[][] a = new int[c1.length+1][c2.length+1];

		int max = 0;
		for(int i=1; i<a.length; i++){
			for(int j=1; j<a[i].length; j++){
				if(c1[i-1]==c2[j-1]) {
					 ; //填空
					if(a[i][j] > max) max = a[i][j];
				}
			}
		}
		return max;
	}

	public static void main(String[] args){
		int n = f("abcdkkk", "baabcdadabc");
		System.out.println(n);
	}
}

import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.List;
import java.util.Scanner;

public class Main{
	//	public static int [] a = new int[20];

	public static void main(String[] args){

		Scanner cin = new Scanner(System.in);
		List<Data> list = new ArrayList<Data>();
		int x, y, z;  //AA/BB/CC
		String str = cin.next();
		x = (int)(str.charAt(0)-'0') * 10 + (int)(str.charAt(1)-'0');
		y = (int)(str.charAt(3)-'0') * 10 + (int)(str.charAt(4)-'0');
		z = (int)(str.charAt(6)-'0') * 10 + (int)(str.charAt(7)-'0');
		int xx = x, yy = y, zz = z;
		
		//		System.out.println(x + "; " + y + "; " + z);
		if((x >= 0 && x <= 59) || (x >= 60 && x <= 99)) {
			int year = 0;
			if(x >= 0 && x <= 59 ) {
				year = x + 2000;
			}
			else {
				year = x + 1900;
			}
			int run = 0;
			if(year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
				run = 1;
//			System.out.println( year + " test+ " + run);
			if(y >= 1 && y <= 12) {
				if(y == 1 || y == 3 || y == 5 || y == 7 || y == 8 || y == 10 || y == 12) {
					if(z >= 1 && z <= 31) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 0) {
					if(z >= 1 && z <= 28) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 1) {
					if(z >= 1 && z <= 29) {
						list.add(new Data(x,y,z));
					}
				}
				else {
					if(z >= 1 && z <= 30) {
						list.add(new Data(x,y,z));
					}
				}
			}
		}
		x = zz; y = yy; z = xx;
		if((x >= 0 && x <= 59) || (x >= 60 && x <= 99)) {
			int year = 0;
			if(x >= 0 && x <= 59 ) {
				year = x + 2000;
			}
			else {
				year = x + 1900;
			}
			int run = 0;
			if(year % 400 == 0 || (year % 100 == 1 && year % 4 == 0))
				run = 1;
			if(y >= 1 && y <= 12) {
				if(y == 1 || y == 3 || y == 5 || y == 7 || y == 8 || y == 10 || y == 12) {
					if(z >= 1 && z <= 31) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 0) {
					if(z >= 1 && z <= 28) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 1) {
					if(z >= 1 && z <= 29) {
						list.add(new Data(x,y,z));
					}
				}
				else {
					if(z >= 1 && z <= 30) {
						list.add(new Data(x,y,z));
					}
				}
			}
		}
		x = zz; y = xx; z = yy;
		if((x >= 0 && x <= 59) || (x >= 60 && x <= 99)) {
			int year = 0;
			if(x >= 0 && x <= 59 ) {
				year = x + 2000;
			}
			else {
				year = x + 1900;
			}
			int run = 0;
			if(year % 400 == 0 || (year % 100 == 1 && year % 4 == 0))
				run = 1;
			if(y >= 1 && y <= 12) {
				if(y == 1 || y == 3 || y == 5 || y == 7 || y == 8 || y == 10 || y == 12) {
					if(z >= 1 && z <= 31) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 0) {
					if(z >= 1 && z <= 28) {
						list.add(new Data(x,y,z));
					}
				}
				else if (y == 2 && run == 1) {
					if(z >= 1 && z <= 29) {
						list.add(new Data(x,y,z));
					}
				}
				else {
					if(z >= 1 && z <= 30) {
						list.add(new Data(x,y,z));
					}
				}
			}
		}
		System.out.println(list.toString());
		Collections.sort(list, new Comparator<Data>() {
			public int compare(Data y, Data x) {
				if(y.year < x.year) {
					return -1;
				}
				else if(y.year > x.year){
					return 1;
				}
				else {
					if(y.math < x.math) {
						return -1;
					}
					else if(y.math > x.math){
						return 1;
					}
					else {
						if(y.day < x.day) {
							return -1;
						}
						else if(y.day > x.day){
							return 1;
						}
						else {
							return 0;
						}
					}
				}
			}
		});
		
		for(Data d : list) {
			if(d.year >= 60) {
				System.out.print("19" + d.year);
			}
			else {
				System.out.print("20");
				if(d.year >= 10) {
					System.out.print(d.year);
				}
				else {
					System.out.print("0" + d.year);
				}
				if(d.math >= 10) {
					System.out.print("/"+ d.math);
				}
				else {
					System.out.print("/0"+ d.math);
				}
				if(d.day >= 10) {
					System.out.print("/"+ d.day);
				}
				else {
					System.out.print("/0"+ d.day);
				}
			}
			System.out.println();
		}
		
	}

}

class Data{
	int year;
	int math;
	int day;
	Data(int y, int m, int d){
		this.year = y;
		this.math = m;
		this.day = d;
	}
	@Override
	public String toString() {
		return "Data [year=" + year + ", math=" + math + ", day=" + day + "]";
	}
}
/*
02/03/04
06/05/04
04/02/29
05/02/29
 */

import java.util.Scanner;

public class Main{
	public static int a[] = new int[104];
	public static int dp[] = new int[10008];
	
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		int n;
		n = cin.nextInt();
		int flag = 1;
		for(int i = 0; i < n; i++) {
			a[i] = cin.nextInt();
		}
		flag = a[0];
		for(int i = 1; i < n; i++) {
			flag = gcd(flag, a[i]);
			if(flag == 1) {  // 如果有互质的则一定是有限个了
				break;
			}
		}
		if(flag != 1) { 
			System.err.println("INF");
			return ;
		}
		
		dp[0] = 1; // 标记为可以凑出
		for(int i = 0; i < n; i++) {
			for(int j = a[i]; j <= 10004; j++) {
				if(dp[j - a[i]] == 1) { //如果可以凑出来，进行标记
					dp[j] = 1;		//能组合的全是2的倍数了，非2的倍数就取不到了
				}
			}
		}
		int ans = 0;
		for(int i = 0; i < 10004; i++) {
			if(dp[i] == 0) {
				ans++;
			}
		}
		System.out.println(ans);
	}

	public static int gcd(int a, int b) {
		return b == 0 ? a : gcd(b, a % b);
	} 
	
}

import java.util.Scanner;

public class Main{
	public static int w[] = new int[100005];
	public static int h[] = new int[100005];
	public static int n;
	public static int k;
	
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		n = cin.nextInt();
		k = cin.nextInt();
		
		int max = -1;
		for(int i = 0; i < n; i++) {
			w[i] = cin.nextInt();
			h[i] = cin.nextInt();
			max = Math.max(max, w[i]);
			max = Math.max(max, h[i]);
		}
		
		int left = 1, right = 100000;
		// 或者用最大值：max
		right = max;
		int mid;
		// 二分查找可能的值：搜索空间：1 ：100000
		while(left < right) {
			mid = left + (right - left) / 2;
			if(slove(mid) == 1) {
				left = mid + 1;
			}
			else {
				right = mid - 1;
			}
//			System.out.println("--" + mid);
		}
		System.out.println(left - 1);
	}
	
	public static int slove(int s) {
		int cnt = 0;
		for(int i = 0; i < n; i++) {
			cnt += w[i] / s * h[i] / s;
		}
		if(cnt >= k) {
			return 1;
		}
		return 0;
	}
}

import java.util.Scanner;

//0<N,V≤1000  表示物品数量和背包容积。
//0<vi,wi≤1000 体积和 价值
public class Main{
	public static int a[] = new int[100005];
	public static int cnt[] = new int[100005];
	
	public static void main(String[] args) {
		Scanner cin = new Scanner(System.in);
		int n, k;
		n = cin.nextInt();
		k = cin.nextInt();
		
		int ans = 0;
		for(int i = 1; i <= n; i++) {
			a[i] = cin.nextInt();
			a[i] = (a[i - 1] + a[i]) % k;
			ans += cnt[a[i]];
			cnt[a[i]]++;
		}
		
//		for(int i = 0 ; i < k; i++) {
//			System.out.println(cnt[i]);
//		}
		
		System.out.println(ans + cnt[0]);
		
	}
	
}