Movatterモバイル変換


[0]ホーム

URL:


Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

Sign up
Appearance settings

Commitfba4231

Browse files
authored
Improved task 3283
1 parent25bbea3 commitfba4231

File tree

1 file changed

+74
-62
lines changed
  • src/main/java/g3201_3300/s3283_maximum_number_of_moves_to_kill_all_pawns

1 file changed

+74
-62
lines changed
Lines changed: 74 additions & 62 deletions
Original file line numberDiff line numberDiff line change
@@ -1,86 +1,98 @@
11
packageg3201_3300.s3283_maximum_number_of_moves_to_kill_all_pawns;
22

33
// #Hard #Array #Math #Breadth_First_Search #Bit_Manipulation #Bitmask #Game_Theory
4-
// #2024_09_09_Time_250_ms_(98.43%)_Space_50.1_MB_(66.27%)
4+
// #2025_03_22_Time_126_ms_(100.00%)_Space_48.23_MB_(72.09%)
55

6-
importjava.util.LinkedList;
6+
importjava.util.ArrayDeque;
77
importjava.util.Queue;
88

99
publicclassSolution {
10-
privatestaticfinalint[][]KNIGHT_MOVES = {
11-
{-2, -1}, {-2,1}, {-1, -2}, {-1,2},
12-
{1, -2}, {1,2}, {2, -1}, {2,1}
10+
privatestaticfinalint[][]DIRECTIONS = {
11+
{2,1}, {1,2}, {-1,2}, {-2,1}, {-2, -1}, {-1, -2}, {1, -2}, {2, -1}
1312
};
14-
privateint[][]distances;
15-
privateInteger[][]memo;
1613

17-
publicintmaxMoves(intkx,intky,int[][]positions) {
14+
privatevoidinitializePositions(int[][]positions,int[][]pos,intkx,intky) {
1815
intn =positions.length;
19-
distances =newint[n +1][n +1];
20-
memo =newInteger[n +1][1 <<n];
21-
// Calculate distances between all pairs of positions (including knight's initial position)
2216
for (inti =0;i <n;i++) {
23-
distances[n][i] =calculateMoves(kx,ky,positions[i][0],positions[i][1]);
24-
for (intj =i +1;j <n;j++) {
25-
intdist =
26-
calculateMoves(
27-
positions[i][0],positions[i][1],positions[j][0],positions[j][1]);
28-
distances[i][j] =distances[j][i] =dist;
29-
}
17+
intx =positions[i][0];
18+
inty =positions[i][1];
19+
pos[x][y] =i;
3020
}
31-
returnminimax(n, (1 <<n) -1,true);
21+
pos[kx][ky] =n;
3222
}
3323

34-
privateintminimax(intlastPos,intremainingPawns,booleanisAlice) {
35-
if (remainingPawns ==0) {
36-
return0;
37-
}
38-
if (memo[lastPos][remainingPawns] !=null) {
39-
returnmemo[lastPos][remainingPawns];
40-
}
41-
intresult =isAlice ?0 :Integer.MAX_VALUE;
42-
for (inti =0;i <distances.length -1;i++) {
43-
if ((remainingPawns & (1 <<i)) !=0) {
44-
intnewRemainingPawns =remainingPawns & ~(1 <<i);
45-
intmoveValue =distances[lastPos][i] +minimax(i,newRemainingPawns, !isAlice);
46-
47-
if (isAlice) {
48-
result =Math.max(result,moveValue);
49-
}else {
50-
result =Math.min(result,moveValue);
24+
privatevoidcalculateDistances(int[][]positions,int[][]pos,int[][]distances) {
25+
intn =positions.length;
26+
for (inti =0;i <n;i++) {
27+
intcount =n -i;
28+
boolean[][]visited =newboolean[50][50];
29+
visited[positions[i][0]][positions[i][1]] =true;
30+
Queue<int[]>que =newArrayDeque<>();
31+
que.offer(newint[] {positions[i][0],positions[i][1]});
32+
intsteps =1;
33+
while (!que.isEmpty() &&count >0) {
34+
intsize =que.size();
35+
while (size-- >0) {
36+
int[]cur =que.poll();
37+
intx =cur[0];
38+
inty =cur[1];
39+
for (int[]d :DIRECTIONS) {
40+
intnx =x +d[0];
41+
intny =y +d[1];
42+
if (0 <=nx &&nx <50 &&0 <=ny &&ny <50 && !visited[nx][ny]) {
43+
que.offer(newint[] {nx,ny});
44+
visited[nx][ny] =true;
45+
intj =pos[nx][ny];
46+
if (j >i) {
47+
distances[i][j] =distances[j][i] =steps;
48+
if (--count ==0) {
49+
break;
50+
}
51+
}
52+
}
53+
}
54+
if (count ==0) {
55+
break;
56+
}
5157
}
58+
steps++;
5259
}
5360
}
54-
memo[lastPos][remainingPawns] =result;
55-
returnresult;
5661
}
5762

58-
privateintcalculateMoves(intx1,inty1,intx2,inty2) {
59-
if (x1 ==x2 &&y1 ==y2) {
60-
return0;
61-
}
62-
boolean[][]visited =newboolean[50][50];
63-
Queue<int[]>queue =newLinkedList<>();
64-
queue.offer(newint[] {x1,y1,0});
65-
visited[x1][y1] =true;
66-
while (!queue.isEmpty()) {
67-
int[]current =queue.poll();
68-
intx =current[0];
69-
inty =current[1];
70-
intmoves =current[2];
71-
for (int[]move :KNIGHT_MOVES) {
72-
intnx =x +move[0];
73-
intny =y +move[1];
74-
if (nx ==x2 &&ny ==y2) {
75-
returnmoves +1;
76-
}
77-
if (nx >=0 &&nx <50 &&ny >=0 &&ny <50 && !visited[nx][ny]) {
78-
queue.offer(newint[] {nx,ny,moves +1});
79-
visited[nx][ny] =true;
63+
privateintcalculateDP(intn,int[][]distances) {
64+
intm = (1 <<n) -1;
65+
int[][]dp =newint[1 <<n][n +1];
66+
for (intmask =1;mask < (1 <<n);mask++) {
67+
booleanisEven = (Integer.bitCount(m ^mask)) %2 ==0;
68+
for (inti =0;i <=n;i++) {
69+
intresult =0;
70+
if (isEven) {
71+
for (intj =0;j <n;j++) {
72+
if ((mask & (1 <<j)) >0) {
73+
result =Math.max(result,dp[mask ^ (1 <<j)][j] +distances[i][j]);
74+
}
75+
}
76+
}else {
77+
result =Integer.MAX_VALUE;
78+
for (intj =0;j <n;j++) {
79+
if ((mask & (1 <<j)) >0) {
80+
result =Math.min(result,dp[mask ^ (1 <<j)][j] +distances[i][j]);
81+
}
82+
}
8083
}
84+
dp[mask][i] =result;
8185
}
8286
}
83-
// Should never reach here if input is valid
84-
return -1;
87+
returndp[m][n];
88+
}
89+
90+
publicintmaxMoves(intkx,intky,int[][]positions) {
91+
intn =positions.length;
92+
int[][]pos =newint[50][50];
93+
initializePositions(positions,pos,kx,ky);
94+
int[][]distances =newint[n +1][n +1];
95+
calculateDistances(positions,pos,distances);
96+
returncalculateDP(n,distances);
8597
}
8698
}

0 commit comments

Comments
 (0)

[8]ページ先頭

©2009-2025 Movatter.jp