POJ2286 The Rotation Game IDA*

基本上是裸的IDA*，细节有点难搞，需要耐心，，老久没一次A过题目了，，

也可以考虑使用bfs求解，但是状态较多无法有效判重，需要每次屏蔽掉两个数只处理一个数

 

#include <cstdio>
#include <cstring>
#include <algorithm>
//#define debug
using std :: min;
const int x1[8] = {0, 1, 3, 7, 12, 16, 21, 23};
const int x2[8] = {0, 2, 4, 9, 13, 18, 22, 24};
const int cent[9] = {0, 7, 8, 9, 12, 13, 16, 17, 18};
const int makex[9] = {0, 1, 2, 3, 4, 2, 1, 4, 3};
const int makep[9] = {0, 1, 1, 2, 2, 2, 2, 1, 1};
int a[5][10];
int num[30];
int mov[30];
int t[30];
int maxd = 0;

int check(void) {
    int cur = t[cent[1]];
    for (int i = 2; i <= 8; i++) if (cur != t[cent[i]]) return 0;
    return cur;
}
void make(int x, int po) {                //    po == 1 up po == 2 down
    if (po == 1) {
        int cur = t[a[x][1]];
        for (int i = 2; i <= 7; i++) t[a[x][i-1]] = t[a[x][i]];
        t[a[x][7]] = cur;
    } else {
        int cur = t[a[x][7]];
        for (int i = 6; i >= 1; i--) t[a[x][i+1]] = t[a[x][i]];
        t[a[x][1]] = cur;
    }
}
int h(int x) {
    int tans = 0;
    for (int i = 1; i <= 8; i++) if (t[cent[i]] != x) tans++;
    return (tans);
}
bool dfs(int d) {
#ifdef debug
    printf("    %d   %d
", t[1], t[2]);
    printf("    %d   %d
", t[3], t[4]);
    for (int i = 5; i <= 11; i++) printf("%d ", t[i]);
    printf("
");
    printf("    %d   %d
", t[12], t[13]);
    for (int i = 14; i <= 20; i++) printf("%d ", t[i]);
    printf("
");
    printf("    %d   %d
", t[21], t[22]);
    printf("    %d   %d
", t[23], t[24]);
    printf("
");
#endif
    if (d == maxd + 1) {
        if (check() > 0) return 1;
        return 0;
    }
    int needd = h(1);
    needd = min(needd, h(2));
    needd = min(needd, h(3));
    if (d + needd - 1 > maxd) return 0;
    for (int i = 1; i <= 8; i++) {
        mov[d] = i;
        make(makex[i], makep[i]);
        if (dfs(d + 1)) return 1;
        if (makep[i] == 1) make(makex[i], 2);
        else make(makex[i], 1);
    }
    return 0; 
    
}
int main () {
    while (scanf("%d", &t[1]) == 1 && t[1]) {
        for (int i = 2; i <= 24; i++) scanf("%d", &t[i]);
        for (int i = 1; i <= 7; i++) a[1][i] = x1[i];
        for (int i = 1; i <= 7; i++) a[2][i] = x2[i];
        for (int i = 1; i <= 7; i++) a[3][i] = i + 4;
        for (int i = 1; i <= 7; i++) a[4][i] = i + 13;
    /*
        for (int i = 1; i <= 7; i++) printf("%d ", a[1][i]);
        printf("
");
        for (int i = 1; i <= 7; i++) printf("%d ", a[2][i]);
        printf("
");
        for (int i = 1; i <= 7; i++) printf("%d ", a[3][i]);
        printf("
");
        for (int i = 1; i <= 7; i++) printf("%d ", a[4][i]);
        printf("
");
    */
        int cur = check();
        if (cur != 0) {
            printf("No moves needed
%d
", cur);
            continue;
        }
        for (maxd = 1; ; maxd++) {
            if (dfs(1)) {
                for (int i = 1; i <= maxd; i++) printf("%c", mov[i] - 1 + 'A');
                printf("
");
                printf("%d
", check());
                break;
            }
        }
    }
    return 0;
}