阿里巴巴java后端实习 3.29笔试复盘
题目写了个大概，仅供自己记录~
1、题目大致有n个人投票，每个人可以投k票，已知这n个人投给小明的票数分别是ai，则k最少为多少可以保证我获胜
输入：
5
2 2 2 3 4
输出：
6
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
if(n < 1) return;
int[] other = new int[n];
int sum = 0,sumMe = 0,k=0;
for (int i = 0; i < n; i++) {
other[i] = sc.nextInt();
sum+= other[i];
k = Math.max(k, other[i]);
}
sumMe = getTotal(other,k);
for (int i = k;; i++) {
if(sumMe > sum) {
System.out.println(i);
break;
}else {
sumMe += n;
}
}
}
private static int getTotal(int[] other, int k) {
int sum = 0;
for (int i = 0; i < other.length; i++) {
sum += (k-other[i]);
}
return sum;
} 2、有n个车站，m条路，接着输出车站a、b之间的距离，从某个车站出发可以到达的最少的车站，如果个数一样，输出编号大的车站 第二题没ac，只是记录
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int T = sc.nextInt();
while (T-- > 0) {
int n = sc.nextInt();
int m = sc.nextInt();
int d = sc.nextInt();
// 输入m行数据
int[][] matrix = new int[n][n];
boolean[][] flag = new boolean[n][n];
for (int k = 1; k <= m; k++) {
int i = sc.nextInt();
int j = sc.nextInt();
int w = sc.nextInt();
matrix[i][j] = w;
matrix[j][i] = w;
flag[i][j] = true;
flag[j][i] = true;
}
// 初始化到达矩阵
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix[i].length; j++) {
if (i == j) {
matrix[i][j] = 0;
flag[i][j] = true;
} else if (matrix[i][j] == 0) {
flag[i][j] = false;
}
}
}
// 不能直接到达，可能可以间接到达
for (int i = 0; i < matrix.length; i++) {
for (int j = 0; j < matrix[i].length; j++) {
if (flag[i][j] == false) {
int min = Integer.MAX_VALUE;
for (int k = 1; k < j; k++) {
if (flag[i][k] && flag[k][j-k]) {
min = Math.min(matrix[i][k] + matrix[k][j-k], min);
matrix[i][j] = min;
matrix[j][i] = min;
flag[i][j] = true;
}
}
}
}
}
// 计算开始
int minCount = n, minCity = n - 1;// 最小的是城市0
for (int i = matrix.length - 1; i >= 0; i--) {
int sum = 0, count = 0;
for (int j = 0; j < matrix[i].length; j++) {
if (!flag[i][j]) {
continue;
} else {
if (matrix[i][j] + sum <= d) {
sum += matrix[i][j];
count++;
} else {
continue;
}
}
}
if (minCount > count) {
minCount = count;
minCity = i;
}
}
System.out.println(minCity);
}
} 
