当时看到这个题只想到了分解质因数和判断什么时候输出-1，忘记输出的时候打乱他们的顺序了。
思路：
第一步：找出当前数的所有质因数和他们出现的次数，我将他们放入了一个存储long[]类型的Arraylist中。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
| List<long[]> list = new ArrayList<>();
for(long i = 2L; i <= x / i ; i++) {
int nums = 0;
while (x % i == 0) {
x = x / i;
nums++;
}
if(nums != 0) {
list.add(new long[]{i, nums});
}
}
if(x > 1) list.add(new long[]{x, 1});
|
第二步：排序判断-1的情况，因为当最大的数中间的间隙不能被填满，那么两个数就相邻，输出-1
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
| long sum = 0;
for (long[] longs : list) {
sum += longs[1];
}
list.sort(Comparator.comparing(o -> (-o[1])));
long val = list.get(0)[0];
long max = list.get(0)[1];
list.remove(0);
if(sum - max < max - 1) {
System.out.println(-1);
return;
}
|
第三步：将出现次数最多的质数分成若干份，每份依次插入到后面的质数中间，除了第一份和出现次数第二多的质数多1，剩下的依次和出现其他次数的质数的数量相等，知道出现次数最多的质数被分完。然后依次输出遍历质因数，每输出一次将该质因数的个数减一。
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
| if(list.size() >= 1) {
long temp = list.get(0)[1];
if(temp < max) {
list.add(0, new long[]{val, temp + 1});
max = max - temp - 1;
}else{
list.add(0, new long[]{val, temp});
max = max - temp;
}
}
for(int i = 2; ; i = i + 2) {
if(i >= list.size() || max <= 0) {
break;
}
long temp = list.get(i)[1];
if(max <= temp) {
list.add(i, new long[]{val, max});
max = 0;
break;
}
max -= temp;
list.add(i,new long[]{val, temp});
}
if(max != 0) list.add(new long[]{val, max});
n = list.size();
System.out.println(sum);
max = list.get(0)[1];
for(int i = 0; i < max; i++) {
for(int j = 0; j < n; j++) {
if(list.get(j)[1] != 0) {
bw.write(list.get(j)[0] + " ");
list.get(j)[1] = list.get(j)[1] - 1;
}
}
}
|
*AC代码：*
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
| import java.io.BufferedWriter;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.util.*;
public class Main {
public static void main(String[] args) throws IOException {
BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
Scanner scan = new Scanner(System.in);
long x = scan.nextLong();
if(x == 1) {
System.out.println(-1);
return;
}
Map<Long, Integer> map = new HashMap<>();
List<long[]> list = new ArrayList<>();
for(long i = 2L; i <= x / i ; i++) {
int nums = 0;
while (x % i == 0) {
x = x / i;
nums++;
}
if(nums != 0) {
list.add(new long[]{i, nums});
}
}
if(x > 1) list.add(new long[]{x, 1});
int n = list.size();
long sum = 0;
for (long[] longs : list) {
sum += longs[1];
}
list.sort(Comparator.comparing(o -> (-o[1])));
long val = list.get(0)[0];
long max = list.get(0)[1];
list.remove(0);
if(sum - max < max - 1) {
System.out.println(-1);
return;
}
if(list.size() >= 1) {
long temp = list.get(0)[1];
if(temp < max) {
list.add(0, new long[]{val, temp + 1});
max = max - temp - 1;
}else{
list.add(0, new long[]{val, temp});
max = max - temp;
}
}
for(int i = 2; ; i = i + 2) {
if(i >= list.size() || max <= 0) {
break;
}
long temp = list.get(i)[1];
if(max <= temp) {
list.add(i, new long[]{val, max});
max = 0;
break;
}
max -= temp;
list.add(i,new long[]{val, temp});
}
if(max != 0) list.add(new long[]{val, max});
n = list.size();
System.out.println(sum);
max = list.get(0)[1];
for(int i = 0; i < max; i++) {
for(int j = 0; j < n; j++) {
if(list.get(j)[1] != 0) {
bw.write(list.get(j)[0] + " ");
list.get(j)[1] = list.get(j)[1] - 1;
}
}
}
bw.flush();
bw.close();
}
}
|
