多校-HDU 5351 MZL's Border 數學

標籤：

f[1] = ‘b‘, f[2] = ‘a‘, f[i] = f[i - 1] + f[i - 2]

斐波那契數列的字串，給你n和m，前m位中，最長的首碼等於尾碼的長度是多少。1≤n≤1000, 1≤m≤length(f[n])

規律題，雖然我不知道為什麼。

 1 import java.io.*; 2 import java.util.*; 3 import java.math.*; 4 public class Main{ 5     //Scanner cin = Scanner(System.in); 6     static BigInteger f[] = new BigInteger[1005]; 7     public static void main(String[] args){ 8         f[1] = new BigInteger("1"); 9         f[2] = new BigInteger("2");10         for(int i = 3; i <= 1001; i++){11             //f[i].valueOf(f[i - 1);12             //f[i] = f[i - 1];13             f[i] = f[i - 1].add(f[i - 2]);14             //f[i].add(f[i - 2]);15             //System.out.println(f[i]);16         }17         Scanner cin = new Scanner(System.in);18         int T = cin.nextInt();19         int n;20         BigInteger m;21         for(int cas = 1; cas <= T; cas++){22             n = cin.nextInt();23             m = cin.nextBigInteger();24             BigInteger mm = m.add(new BigInteger("1"));25             int p = 0;26             for(int i = 1; i <= 1001; i++){27                 if(f[i].compareTo(mm) > 0){28                     p = i;29                     break;30                 }31             }32             BigInteger ans = m.subtract(f[p - 2]);33             System.out.println(ans.mod(new BigInteger("258280327")));34         }35         36     }37 }

 

多校-HDU 5351 MZL's Border 數學