Algorithm
problem Link : https://onlinejudge.org/index.php?option=onlinejudge&Itemid=8&page=show_problem&problem=1576
In an n×n chessboard, Prince and Princess plays a game. The squares in the chessboard are numbered 1, 2, 3, . . . , n ∗ n, as shown below: Prince stands in square 1, make p jumps and finally reach square n ∗ n. He enters a square at most once. So if we use xp to denote the p-th square he enters, then x1, x2, . . . , xp+1 are all different. Note that x1 = 1 and xp+1 = n ∗ n. Princess does the similar thing – stands in square 1, make q jumps and finally reach square n ∗ n. We use y1, y2, . . . , yq+1 to denote the sequence, and all q + 1 numbers are different. Figure 2 belows show a 3×3 square, a possible route for Prince and a different route for Princess. The Prince moves along the sequence: 1 –> 7 –> 5 –> 4 –> 8 –> 3 –> 9 (Black arrows), while the Princess moves along this sequence: 1 –> 4 –> 3 –> 5 > 6 –> 2 –> 8 –> 9 (White arrow). The King – their father, has just come. “Why move separately? You are brother and sister!” said the King, “Ignore some jumps and make sure that you’re always together.” For example, if the Prince ignores his 2nd, 3rd, 6th jump, he’ll follow the route: 1 –> 4 –> 8 –> 9. If the Princess ignores her 3rd, 4th, 5th, 6th jump, she’ll follow the same route: 1 –> 4 –> 8 –> 9, (The common route is shown in figure 3) thus satisfies the King, shown above. The King wants to know the longest route they can move together, could you tell him? Input The first line of the input contains a single integer t (1 ≤ t ≤ 10), the number of test cases followed. For each case, the first line contains three integers n, p, q (2 ≤ n ≤ 250, 1 ≤ p, q < n ∗ n). The second line contains p + 1 different integers in the range [1 . . . n ∗ n], the sequence of the Prince. The third line contains q + 1 different integers in the range [1 . . . n ∗ n], the sequence of the Princess. Output For each test case, print the case number and the length of longest route. Look at the output for sample input for details.
Sample Input 1 3 6 7 1 7 5 4 8 3 9 1 4 3 5 6 2 8 9
Sample Output Case 1: 4
Code Examples
#1 Code Example with C Programming
Code -
C Programming
#include <bits/stdc++.h>
using namespace std;
int main()
{
int t,n,p,q,v,tc=1;
scanf("%d",&t);
while(t--){
scanf("%d %d %d",&n,&p,&q);
vector<int> lcs; // also lis of position
unordered_map < int,int> valToPos; // valToPos for the prince
for(int i=0;i < =p;i++){
scanf("%d",&v);
valToPos[v] = i;
}
for(int i=0;i < =q;i++){
scanf("%d",&v);
int pos = valToPos[v];
if(pos == 0) continue;
auto insertion = lower_bound(lcs.begin(),lcs.end(),pos);
// greedy, take lower position
if(insertion == lcs.end()) lcs.push_back(pos);
else *insertion = pos;
}
printf("Case %d: %d\n", tc++, lcs.size()+1);
}
}
Input
3 6 7
1 7 5 4 8 3 9
1 4 3 5 6 2 8 9
Output
Demonstration
UVA Online Judge solution - 10635-Prince and Princess - UVA Online Judge solution in C,C++,java