/// Author: Wang, Yen-Jen
#include <cstdio>
#include <algorithm>
using namespace std;
const int MAX_N = 5000 + 7;
const int INF = 0x3f3f3f3f;
int A[MAX_N];
int dp[2][MAX_N<<1][3][3][2];
int main() {
int N, X, Y;
scanf("%d%d%d", &N, &X, &Y);
int M = 0;
for(int i = 1; i <= N; i++) {
scanf("%d",&A[i]);
if(A[i] == X) A[i] = 0;
else if(A[i] == Y) A[i] = 1;
else A[i] = 2, M++;
}
for(int i = 0; i <= M + M; i++) {
for(int j = 0; j < 3; j++) {
for(int k = 0; k < 3; k++) {
for(int l = 0; l < 2; l++) dp[0][i][j][k][l] = INF;
}
}
}
dp[0][M][2][0][0] = 0;
dp[0][M][0][2][1] = 0;
for(int i = 1; i <= N; i++) {
for(int j = 0; j <= M + M; j++) {
for(int k = 0; k < 3; k++) {
for(int x = 0; x < 3; x++) {
for(int y = 0; y < 2; y++) dp[i&1][j][k][x][y] = INF;
}
}
}
for(int j = 0; j <= M + M; j++) {
for(int k = 0; k < 3; k++) {
for(int x = 0; x < 3; x++) {
for(int y = 0; y < 2; y++) {
if(dp[~i&1][j][k][x][y] == INF) continue;
if(A[i] == 0) {
if(y == 0) {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y]);
if(j + 1 <= M + M) {
dp[i&1][j + 1][k][2][1] = min(dp[i&1][j + 1][k][2][1] , dp[~i&1][j][k][x][y] + 1);
}
}
else {
if(k == 0) {
dp[i&1][j][1][x][y] = min(dp[i&1][j][1][x][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][2][x][0] = min(dp[i&1][j + 1][2][x][0] , dp[~i&1][j][k][x][y] + 1);
}
}
else if(k == 1) {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][2][x][0] = min(dp[i&1][j + 1][2][x][0] , dp[~i&1][j][k][x][y] + 1);
}
}
else {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][2][x][1] = min(dp[i&1][j + 1][2][x][1] , dp[~i&1][j][k][x][y] + 1);
}
}
}
}
else if(A[i] == 1) {
if(y == 1) {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y]);
if(j + 1 <= M + M) {
dp[i&1][j + 1][2][x][0] = min(dp[i&1][j + 1][2][x][0] , dp[~i&1][j][k][x][y] + 1);
}
}
else {
if(x == 0) {
dp[i&1][j][k][1][y] = min(dp[i&1][j][k][1][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][k][2][1] = min(dp[i&1][j + 1][k][2][1] , dp[~i&1][j][k][x][y] + 1);
}
}
else if(x == 1) {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][k][2][1] = min(dp[i&1][j + 1][k][2][1] , dp[~i&1][j][k][x][y] + 1);
}
}
else {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y] + 1);
if(j + 1 <= M + M) {
dp[i&1][j + 1][k][2][0] = min(dp[i&1][j + 1][k][2][0] , dp[~i&1][j][k][x][y] + 1);
}
}
}
}
else {
dp[i&1][j][k][x][y] = min(dp[i&1][j][k][x][y] , dp[~i&1][j][k][x][y]);
if(j >= 1) dp[i&1][j - 1][k][x][y] = min(dp[i&1][j - 1][k][x][y] , dp[~i&1][j][k][x][y]);
if(y == 0) {
dp[i&1][j][k][2][1] = min(dp[i&1][j][k][2][1] , dp[~i&1][j][k][x][y]);
}
else {
dp[i&1][j][2][x][0] = min(dp[i&1][j][2][x][0] , dp[~i&1][j][k][x][y]);
}
}
}
}
}
}
}
int ans = INF;
ans = min(ans , dp[N&1][M][2][0][0]);
ans = min(ans , dp[N&1][M][2][2][0]);
ans = min(ans , dp[N&1][M][0][2][1]);
ans = min(ans , dp[N&1][M][2][2][1]);
if(ans == INF) puts("-1");
else printf("%d\n",ans);
return 0;
}
Compilation message
main.cpp: In function 'int main()':
main.cpp:15:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
15 | scanf("%d%d%d", &N, &X, &Y);
| ~~~~~^~~~~~~~~~~~~~~~~~~~~~
main.cpp:18:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
18 | scanf("%d",&A[i]);
| ~~~~~^~~~~~~~~~~~
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
256 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
256 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Incorrect |
0 ms |
256 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
