网易笔试

编程题3道，每题20分。

第一题，一个sql语句，id和name，求表中姓名有重复的人的个数。

public class Main {

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int N = in.nextInt();

if (N != 0) {

List<String> uname = new LinkedList<>();

for (int i = 0; i < N; i++) {

String a = in.next();

String ss = in.next();

uname.add(ss);

}

System.out.println(getSql(uname));

} else

System.out.println(0);

}

private static int getSql(List<String> uname) {

int resInt = 0;

Map<String, Integer> res = new HashMap<>();

for (String s : uname) {

if (!res.containsKey(s)) {

res.put(s, 1);

} else

res.put(s, res.get(s) + 1);

}

for (String s : res.keySet()) {

int res1 = res.get(s);

if (res1 != 1) {

resInt++;

}

}

return resInt;

}

}

第二题，迷宫左手法则多少步能走出迷宫。

左手法则：沿着墙壁走，如果左边没墙壁，就往左走，否则看前面有没有墙壁，没有往前走，否则右面有没有墙壁往右走，否则往后走。

#为墙壁，.为路，S为开始位置，E为结束位置。

public class Main {

static Road road;

public static void main(String[] args) {

Scanner in = new Scanner(System.in);

int N = in.nextInt();

for (int i = 0; i < N; i++) {

int L = in.nextInt();

int W = in.nextInt();

char[][] arr = new char[W][L];

int start1 = 0, start2 = 0;

char[] c;

String s;

for (int j = 0; j < W; j++) {

s = in.next();

c = s.toCharArray();

for (int k = 0; k < L; k++) {

arr[j][k] = c[k];

if (arr[j][k] == 'S') {

start1 = j;

start2 = k;

}

}

}

System.out.println(result(arr, start1 ,start2));

}

}

private static int result(char[][] arr, int start1, int start2) {

int i = start1;

int j = start2;

int ans = 0;

if (i == 0) {

road = Road.DOWN ;

} else if (j == 0) {

road = Road.RIGHT ;

} else if (i == arr.length - 1) {

road = Road.UP ;

} else {

road = Road.LEFT ;

}

int[] ij;

while (arr[i][j] != 'E') {

ans++;

if (!wallLeft(i, j, arr)) {

ij = trunLeft(i, j);

} else if (!wallFront (i, j, arr)) {

ij = forward(i, j);

} else if (!wallRight (i, j, arr)) {

ij = trunRight(i, j);

} else {

ij = back(i, j);

}

i = ij[0];

j = ij[1];

}

return ++ans;

}

private static int[] back(int i, int j) {

int[] ij = new int[2];

if (road == Road.UP) {

road = Road.DOWN ;

i++;

} else if (road == Road. DOWN) {

road = Road.UP ;

i--;

} else if (road == Road. LEFT) {

road = Road.RIGHT ;

j++;

} else {

road = Road.LEFT ;

j--;

}

ij[0] = i;

ij[1] = j;

return ij;

}

private static int[] trunRight(int i, int j) {

int[] ij = new int[2];

if (road == Road.UP) {

road = Road.RIGHT ;

j++;

} else if (road == Road. DOWN) {

road = Road.LEFT ;

j--;

} else if (road == Road. LEFT) {

road = Road.UP ;

i--;

} else {

road = Road.DOWN ;

i++;

}

ij[0] = i;

ij[1] = j;

return ij;

}

private static int[] forward(int i, int j) {

int[] ij = new int[2];

if (road == Road.UP) {

i--;

} else if (road == Road. DOWN) {

i++;

} else if (road == Road. LEFT) {

j--;

} else {

j++;

}

ij[0] = i;

ij[1] = j;

return ij;

}

private static int[] trunLeft(int i, int j) {

int[] ij = new int[2];

if (road == Road.UP) {

road = Road.LEFT ;

j--;

} else if (road == Road. DOWN) {

road = Road.RIGHT ;

j++;

} else if (road == Road. LEFT) {

road = Road.DOWN ;

i++;

} else {

road = Road.UP ;

i--;

}

ij[0] = i;

ij[1] = j;

return ij;

}

private static boolean wallRight(int i, int j, char[][] arr) {

if (road == Road.UP) {

return arr[i][j + 1] == '#';

} else if (road == Road. DOWN) {

return arr[i][j - 1] == '#';

} else if (road == Road. RIGHT) {

return arr[i + 1][j] == '#';

} else

return arr[i - 1][j] == '#';

}

private static boolean wallFront(int i, int j, char[][] arr) {

if (road == Road.UP) {

return arr[i - 1][j] == '#';

} else if (road == Road. DOWN) {

return arr[i + 1][j] == '#';

} else if (road == Road. RIGHT) {

return arr[i][j + 1] == '#';

} else

return arr[i][j - 1] == '#';

}

private static boolean wallLeft(int i, int j, char[][] arr) {

if (road == Road.UP) {

return arr[i][j - 1] == '#';

} else if (road == Road. DOWN) {

return arr[i][j + 1] == '#';

} else if (road == Road. RIGHT) {

return arr[i - 1][j] == '#';

} else

return arr[i + 1][j] == '#';

}

}

enum Road {

UP, DOWN ,LEFT, RIGHT;

}

第二题抠细节扣的我脑壳疼，结果没在结束之前扣完，结束十多分钟后才把两个测试用例通过，但我觉得问题不大。

第三题，没时间做。

求中位数，如果得分等于中位数，则得到奖励，否则不得奖励，求有多少个人得到了奖励。