HDU

来源：互联网发布：物理数据库模型编辑：程序博客网时间：2024/06/07 23:51

直接 dfs 爆搜，从第一个位置开始选填颜色

但是要加一个剪枝，防止超时：剩余的每个颜色的数目都要小于等于没填色颜色的的格子数的一半（奇数的时候要加一）

这份代码写的比较急，很丑，待优化

#include <iostream>#include <cstdio>#include <cstdlib>#include <cstring>#include <string>#include <cmath>#include <set>#include <map>#include <stack>#include <queue>#include <ctype.h>#include <vector>#include <algorithm>#include <sstream>#define PI acos(-1.0)#define in freopen("in.txt", "r", stdin)#define out freopen("out.txt", "w", stdout)using namespace std;typedef long long ll;const int maxn =  7, INF = 0x3f3f3f3f, mod = 1e9 + 7;int T, n, m, k;int mp[maxn][maxn];int a[maxn*maxn], vis[maxn][maxn];int dx[5] = {1, 0, -1, 0};int dy[5] = {0, 1, 0, -1};void init() {    scanf("%d %d %d", &n, &m, &k);    for(int i = 1; i <= k; ++i)        scanf("%d", &a[i]);    memset(mp, 0, sizeof mp);}bool dfs(int x, int y, int cnt) {    if(cnt == n*m) return true;    for(int ii = 0; ii < 4; ++ii) {        int xx = x + dx[ii], yy = y + dy[ii];        if(xx < 1 || xx > n || yy < 1 || yy > m) continue;        if(vis[xx][yy]) continue;        vis[xx][yy] = 1;        int f = 0;        for(int i = 1; i <= k; ++i) {            if(a[i]) {                int j;                for(j = 0; j < 4; ++j) {                    int nx = xx + dx[j], ny = yy + dy[j];                    if(mp[nx][ny] == i) break;                }                if(j == 4) {                    f = 1;                    a[i]--;                    mp[xx][yy] = i;                    int t = (n*m-cnt)/2, f_ = 1;                    for(int i = 1; i <= k; ++i)                    if(a[i] > t) { f_ = 0; break; }                    if(f_ && dfs(xx, yy, cnt+1)) return true;                    a[i]++;                    mp[xx][yy] = 0;                }            }        }        if(f == 0) { vis[xx][yy] = 0; return false; }        vis[xx][yy] = 0;    }    return false;}void solve() {    for(int i = 1; i <= k; ++i) {        a[i]--;        memset(vis, 0, sizeof vis);        vis[1][1] = 1;        mp[1][1] = i;        if(dfs(1, 1, 1)) {            puts("YES");            for(int i = 1; i <= n; ++i) {                for(int j = 1; j <= m; ++j)                    printf("%d%c", mp[i][j], (j == m ? '\n' : ' '));            }            //cout << "++++++++++++++++++++++++2333" << endl;            return;        }        a[i]++;        vis[1][1] = 0;        mp[1][1] = 0;    }    puts("NO");}int main() {    scanf("%d", &T);    int kase = 1;    while(T--) {        init();        printf("Case #%d:\n", kase++);        solve();    }    return 0;}

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