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) 22 #define pfl(n) printf("%I64d ", 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 ", ans); 63 } 64 return 0; 65 }
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) 22 #define pfl(n) printf("%I64d ", 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 ", ans); 65 } 66 return 0; 67 }
% 慎用啊必须，虽然不知道为什么