HDU 5353 Average 贪心

就是贪心啊，不知道为啥总是不过，总是WA
方法不对吗？

将数组扩展一倍，从左到右扫描，大于平均数就给右边的，小于就从右边拿，等于就不变，记录下操作类型。

大于2直接NO，不知道哪错了，自己出了一些数据也都过了

路过的大神多瞄一眼

 

多校每周只有两场，还是尽量把题全过了吧

1 #pragma comment(linker, "/STACK:102400000,102400000")
2 #include <iostream>
3 #include <cstdio>
4 #include <fstream>
5 #include <algorithm>
6 #include <cmath>
7 #include <deque>
8 #include <vector>
9 #include <queue>
10 #include <string>
11 #include <cstring>
12 #include <map>
13 #include <stack>
14 #include <set>
15 #define LL long long
16 #define INF 0x3f3f3f3f
17 #define MAXN 200005
18 using namespace std;
19 struct Node
20 {
21     int x, y;
22     Node(int x = 0, int y = 0):x(x), y(y){};
23 };
24 vector<Node> res;
25 int n;
26 LL sum;
27 LL a[MAXN];
28 int f[MAXN];
29 int main()
30 {
31 #ifndef ONLINE_JUDGE
32     freopen("in.txt", "r", stdin);
33     //freopen("out.txt", "w", stdout);
34 #endif // OPEN_FILE
35    int T;
36    scanf("%d", &T);
37    for(int cas = 1; cas <= T; cas++){
38         scanf("%d", &n);
39         sum = 0;
40         for(int i = 1; i <= n; i++){
41             scanf("%d", &a[i]);
42             a[i + n] = a[i];
43             sum += a[i];
44         }
45         if(sum % n != 0){
46             printf("NO\n");
47             continue;
48         }
49         LL ave = sum / n;
50         memset(f, 0, sizeof(f));
51         bool noans = false;
52         for(int i = 1; i < 2 * n; i++){
53             if(a[i] == ave){
54                 continue;
55             }
56             if(a[i] < ave){
57                 if(ave - a[i] > 2){
58                     noans = true;
59                     break;
60                 }
61                 a[i]++;
62                 a[i + 1]--;
63                 f[i] = 1;
64                 continue;
65             }
66             if(a[i] > ave){
67                 if(a[i] - ave > 2){
68                     noans = true;
69                     break;
70                 }
71                 a[i]--;
72                 a[i + 1]++;
73                 f[i] = -1;
74             }
75         }
76         if(noans){
77             printf("NO\n");
78             continue;
79         }
80         noans = true;
81         int cnt = 1;
82         int pos = 0;
83         for(int i = 2; i <= 2 * n; i++){
84             if(a[i] == a[i - 1]){
85                 cnt++;
86             }
87             else{
88                 cnt = 1;
89             }
90             if(cnt == n){
91                 noans = false;
92                 pos = i;
93                 break;
94             }
95         }
96         if(noans){
97             printf("NO\n");
98             continue;
99         }
100         printf("YES\n");
101         int x, y;
102         res.clear();
103         for(int i = pos - n + 1; i <= pos; i++){
104             if(f[i] == 0){
105                 continue;
106             }
107             if(f[i] == 1){
108                 x = i + 1;
109                 y = i;
110             }
111             else{
112                 x = i;
113                 y = i + 1;
114             }
115             if(x > n){
116                 x -= n;
117             }
118             if(y > n){
119                 y -= n;
120             }
121             res.push_back(Node(x, y));
122         }
123         printf("%d\n", res.size());
124         for(int i = 0; i < res.size(); i++){
125             printf("%d %d\n", res[i].x, res[i].y);
126         }
127    }
128 }