题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=4576
坑大发了，居然加 % 也会超时；
1 #include <cstdio>
2 #include <iostream>
3 #include <sstream>
4 #include <cmath>
5 #include <cstring>
6 #include <cstdlib>
7 #include <string>
8 #include <vector>
9 #include <map>
10 #include <set>
11 #include <queue>
12 #include <stack>
13 #include <algorithm>
14 using namespace std;
15 #define ll long long
16 #define _cle(m, a) memset(m, a, sizeof(m))
17 #define repu(i, a, b) for(int i = a; i < b; i++)
18 #define repd(i, a, b) for(int i = b; i >= a; i--)
19 #define sfi(n) scanf("%d", &n)
20 #define sfl(n) scanf("%I64d", &n)
21 #define pfi(n) printf("%d\n", n)
22 #define pfl(n) printf("%I64d\n", n)
23 #define MAXN 1000005
24 int n, l, m, r, d;
25 int t = 0, mm;
26 double dp[2][205];
27 int main()
28 {
29 while(~scanf("%d%d%d%d", &n, &m, &l, &r) && (n + m + l + r))
30 {
31 t = 0;
32 repu(i, 0, n + 1) dp[0][i] = 0.0;
33 dp[0][1] = 1.0;
34 int c;
35 repu(i, 0, m)
36 {
37 sfi(d);
38 if(l == 1 && r == n) continue;
39 c = d / n;
40 mm = d - n * c;
41 if(mm)
42 {
43 t = !t;
44 repu(j, 1, n + 1)
45 {
46 int lt, rt;
47 if((n + (j - mm)) >= n) lt = (n + (j - mm)) - n;
48 else lt = (n + (j - mm));
49 if((j + mm) >= n) rt = (j + mm) - n;
50 else rt = (j + mm);
51 if(lt == 0) lt = n;
52 if(rt == 0) rt = n;
53 dp[t][j] = (dp[!t][lt] + dp[!t][rt]) / 2.0;
54 //cout<<j<<" :"<<dp[t][j]<<endl;
55 }
56 }
57 }
58 double ans = 0.0;
59 if(l == 1 && r == n) ans = 1.0;
60 else
61 repu(i, l, r + 1) ans += dp[t][i];
62 printf("%.4lf\n", ans);
63 }
64 return 0;
65 }
AC
1 #include <cstdio>
2 #include <iostream>
3 #include <sstream>
4 #include <cmath>
5 #include <cstring>
6 #include <cstdlib>
7 #include <string>
8 #include <vector>
9 #include <map>
10 #include <set>
11 #include <queue>
12 #include <stack>
13 #include <algorithm>
14 using namespace std;
15 #define ll long long
16 #define _cle(m, a) memset(m, a, sizeof(m))
17 #define repu(i, a, b) for(int i = a; i < b; i++)
18 #define repd(i, a, b) for(int i = b; i >= a; i--)
19 #define sfi(n) scanf("%d", &n)
20 #define sfl(n) scanf("%I64d", &n)
21 #define pfi(n) printf("%d\n", n)
22 #define pfl(n) printf("%I64d\n", n)
23 #define MAXN 1000005
24 int n, l, m, r, d;
25 int t = 0, mm;
26 double dp[2][205];
27 int main()
28 {
29 while(~scanf("%d%d%d%d", &n, &m, &l, &r) && (n + m + l + r))
30 {
31 t = 0;
32 repu(i, 0, n + 1) dp[0][i] = 0.0;
33 dp[0][1] = 1.0;
34 int c;
35 repu(i, 0, m)
36 {
37 sfi(d);
38 if(l == 1 && r == n) continue;
39 c = d / n;
40 mm = d - n * c;
41 if(mm)
42 {
43 t = !t;
44 repu(j, 1, n + 1)
45 {
46 int lt, rt;
47 lt = (n + (j - mm)) % n;
48 rt = (j + mm) % n;
49 // if((n + (j - mm)) >= n) lt = (n + (j - mm)) - n;
50 // else lt = (n + (j - mm));
51 // if((j + mm) >= n) rt = (j + mm) - n;
52 // else rt = (j + mm);
53 if(lt == 0) lt = n;
54 if(rt == 0) rt = n;
55 dp[t][j] = (dp[!t][lt] + dp[!t][rt]) / 2.0;
56 //cout<<j<<" :"<<dp[t][j]<<endl;
57 }
58 }
59 }
60 double ans = 0.0;
61 if(l == 1 && r == n) ans = 1.0;
62 else
63 repu(i, l, r + 1) ans += dp[t][i];
64 printf("%.4lf\n", ans);
65 }
66 return 0;
67 }
TLE
% 慎用啊必须，虽然不知道为什么
时间： 2024-10-16 09:31:45