数独，解题

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package acm;import java.util.Scanner;/** * http://acm.nyist.net/JudgeOnline/problem.php?pid=722 * @author yes.yuan * sample_input18 0 0 0 0 0 0 0 00 0 3 6 0 0 0 0 00 7 0 0 9 0 2 0 00 5 0 0 0 7 0 0 00 0 0 0 4 5 7 0 00 0 0 1 0 0 0 3 00 0 1 0 0 0 0 6 80 0 8 5 0 0 0 1 00 9 0 0 0 0 4 0 0result8 1 2 7 5 3 6 4 9 9 4 3 6 8 2 1 7 5 6 7 5 4 9 1 2 8 3 1 5 4 2 3 7 8 9 6 3 6 9 8 4 5 7 2 1 2 8 7 1 6 9 5 3 4 5 2 1 9 7 4 3 6 8 4 3 8 5 2 6 9 1 7 7 9 6 3 1 8 4 5 2  */public class acm722 {    public static void main(String[] args) throws Exception {        Scanner sc = new Scanner(System.in);        int t = sc.nextInt();        long time = System.currentTimeMillis();        for (int tc = 0; tc < t; tc++) {            map = new int[size][size];            data = new int[9*9][2];            nums = new int[9*9][10];            len = 0;            for (int x = 0; x < size; x++)                for (int y = 0; y < size; y++) {                    map[x][y] = sc.nextInt();                    if(map[x][y] == 0) {                        data[len][0] = x;                        data[len][1] = y;                        len++;                    }                }            for (int i = 0; i < len; i++) {                int x = data[i][0];                int y = data[i][1];                nums[i] = nums( x, y);            }            if(dfs(0, 0)){                for (int i = 0; i < size; i++) {                    for (int j = 0; j < size; j++) {                        System.out.print(map[i][j] +" ");                    }                    System.out.println();                }            }        }        System.out.println("time="+(System.currentTimeMillis()-time));    }    static int  size = 9,map[][], data[][], nums[][], len;    static boolean dfs(int step1,int step2){        int x = data[step1][0],y = data[step1][1];        if(step1==len)  return true;        for (int i = step2; nums[step1][i]!=-1; i++) {            map[x][y] = nums[step1][i];            if(inrangrhor(x,y)&&inrangrver(x,y)&&inrangrblock(x, y)) {                if(dfs(step1+1,0)) {                    return true;                }            }            map[x][y] = 0;        }        return false;    }    static boolean inrangrhor(int x,int ty){        int key = map[x][ty];        for (int y = 0; y < size; y++) {            if(y!=ty&&map[x][y]!=0){                if(key==map[x][y]) {                    return false;                }            }        }        return true;    }    static boolean inrangrver(int tx,int y){        int key = map[tx][y];        for (int x = 0; x < size; x++) {            if(x!=tx&&map[x][y]!=0){                if(key==map[x][y]) {                    return false;                }            }        }        return true;    }    static boolean inrangrblock(int tx,int ty){        int key = map[tx][ty];        int x = tx/3;        int y = ty/3;        for (int i = x*3; i < x*3+3; i++)             for (int j = y*3; j < y*3+3; j++) {                if(i!=tx&&j!=ty&&map[i][j]!=0){                    if(key==map[i][j]) {                        return false;                    }                }            }        return true;    }    static int[] nums(int tx,int ty){        int d[] = new int[10];        for (int y = 0; y < size; y++)            if(map[tx][y]!=0){                d[map[tx][y]] = 1;            }        for (int x = 0; x < size; x++)             if(map[x][ty]!=0){                d[map[x][ty]] = 1;            }        int x = tx/3;        int y = ty/3;        for (int i = x*3; i < x*3+3; i++)            for (int j = y*3; j < y*3+3; j++)                if(map[x][ty]!=0) {                    d[map[x][ty]] = 1;                }        int result[] = new int[10],cnt = 0;        for (int i = 1; i < d.length; i++)            if(d[i]==0){                result[cnt++] = i;            }        result[cnt++] = -1;        return result;    }}
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