正睿20NOIp前冲刺day14
估分：100+100+50=250
实际：100+100+50=250
T1:
b[i]表示不大于i的在a中的最大值，之后枚举每一个ai，再枚举他的倍数，就得出来了
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 using namespace std; 6 7 inline int read() 8 { 9 int x = 0, f = 0; 10 char ch = getchar(); 11 while (!isdigit(ch)) f = ch == '-', ch = getchar(); 12 while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar(); 13 return f ? -x : x; 14 } 15 16 const int N = 2000010; 17 18 int n; 19 int a[N], b[N]; 20 21 int main() 22 { 23 n = read(); 24 for (int i = 1; i <= n; i++) a[i] = read(); 25 sort(a + 1, a + 1 + n); 26 27 if (n <= 1000) 28 { 29 int ans = 0; 30 for (int i = 1; i <= n; i++) 31 { 32 for (int j = i + 1; j <= n; j++) ans = max(ans, a[j] % a[i]); 33 } 34 printf("%d", ans); 35 } 36 else 37 { 38 n = unique(a + 1, a + 1 + n) - a - 1; 39 for (int i = 2000000, j = n; i; i--) 40 { 41 while (j && a[j] >= i) j--; 42 b[i] = a[j]; 43 } 44 45 int ans = 0; 46 for (int i = 1; i <= n; i++) 47 { 48 for (int j = 2; j * a[i] <= 2000000; j++) 49 ans = max(ans, b[a[i] * j] % a[i]); 50 } 51 printf("%d", ans); 52 } 53 return 0; 54 }
T2:
因为相撞掉头，所以每辆车在序列中的排名是不变的，所以我们把相撞掉头看成直接穿过车辆继续走不掉头，询问的时候看排名就行了，查询就直接二分
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 using namespace std; 6 7 inline int read() 8 { 9 int x = 0, f = 0; 10 char ch = getchar(); 11 while (!isdigit(ch)) f = ch == '-', ch = getchar(); 12 while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar(); 13 return f ? -x : x; 14 } 15 16 const int N = 200010; 17 18 int n; 19 int a[N], c[N], id[N]; 20 int Ld[N], Rd[N], cntr, cntl; 21 char dir[N]; 22 23 bool cmp(int x, int y) { return a[x] < a[y]; } 24 25 int main() 26 { 27 //freopen("input.txt","r",stdin); 28 int q; 29 n = read(), q = read(); 30 for (int i = 1; i <= n; i++) a[i] = read(), c[i] = i; 31 sort(c + 1, c + 1 + n, cmp); 32 sort(a + 1, a + 1 + n); 33 for (int i = 1; i <= n; i++) id[c[i]] = i; 34 35 scanf("%s", dir + 1); 36 for (int i = 1; i <= n; i++) 37 { 38 if (dir[i] == 'L') Ld[++cntl] = a[id[i]]; 39 else Rd[++cntr] = a[id[i]]; 40 } 41 42 sort(Ld + 1, Ld + 1 + cntl); 43 sort(Rd + 1, Rd + 1 + cntr); 44 while (q--) 45 { 46 int x = read(), t = read(); 47 48 x = id[x]; 49 int lx = x, rx = 0; 50 if (lx > cntl) lx = cntl, rx = x - cntl; 51 for (int i = 25; ~i; i--) 52 { 53 int la = lx - (1 << i), ra = rx + (1 << i); 54 if (la <= 0 || ra > cntr) continue; 55 if (Ld[la] - t > Rd[ra] + t) lx = la, rx = ra; 56 } 57 58 int ans = abs(Ld[lx] - t); 59 if (rx > 0 && Ld[lx] - t < Rd[rx] + t) ans = abs(Rd[rx] + t); 60 if (rx + 1 <= cntr && Ld[lx] - t > Rd[rx + 1] + t) ans = abs(Rd[rx + 1] + t); 61 printf("%d\n", ans); 62 } 63 return 0; 64 }
T3:
时间不够敲了，就一个随机数
敲了一下午的7k的代码过了五万八个点
1 #include<cstdio> 2 #include<cstring> 3 #include<iostream> 4 #include<algorithm> 5 using namespace std; 6 7 inline int read() 8 { 9 int x = 0, f = 0; 10 char ch = getchar(); 11 while (!isdigit(ch)) f = ch == '-', ch = getchar(); 12 while (isdigit(ch)) x = x * 10 + ch - '0', ch = getchar(); 13 return f ? -x : x; 14 } 15 16 inline void Stru(int a[10], int sid[][10]) 17 { 18 sid[1][0] = a[1] * 100 + a[2]; 19 sid[2][0] = a[3] / 100 % 100 *100 + a[4] / 100 % 100; 20 sid[3][0] = a[5] * 100 + a[6]; 21 sid[4][0] = a[7] * 100 + a[8]; 22 sid[5][0] = a[3] / 10000 % 100 * 100 + a[4] / 10000 % 100; 23 sid[6][0] = a[3] % 100 *100 + a[4] % 100; 24 } 25 26 inline void Whi(int sid[]) 27 { 28 for (int i = 1; i < 4; i++) 29 { 30 int x = sid[i - 1]; 31 sid[i] = x % 10 * 10 + x / 10 % 10 * 1000 + x / 100 % 10 + x / 1000 * 100; 32 } 33 } 34 35 int sid1[10][10], ned[10][10]; 36 37 inline bool check() 38 { 39 int sub[10] = { 0 }; 40 for (int i = 1; i <= 6; i++) 41 { 42 int a = sid1 [i][0], b = ned[i][0]; 43 while (a) 44 { 45 int x = a % 10, y = b % 10; 46 a /= 10, b /= 10; 47 if (!sub[x]) sub[x] = y; 48 else if (sub[x] != y) return false; 49 } 50 } 51 return true; 52 } 53 54 inline void Clowise(int x) 55 { 56 for (int i = 0; i < 3; i++) swap(sid1[x][i], sid1[x][i + 1]); 57 } 58 59 inline void Rev_Clowise(int x) 60 { 61 for (int i = 3; i; i--) swap(sid1[x][i], sid1[x][i - 1]); 62 } 63 64 inline void Oper1() 65 { 66 swap(sid1[4], sid1[6]); 67 swap(sid1[5], sid1[4]); 68 swap(sid1[2], sid1[5]); 69 70 Clowise(2); 71 Clowise(4); 72 Clowise(5); 73 Clowise(6); 74 Clowise(1); 75 Rev_Clowise(3); 76 } 77 78 inline void Oper2() 79 { 80 swap(sid1[1], sid1[6]); 81 swap(sid1[5], sid1[1]); 82 swap(sid1[3], sid1[5]); 83 84 Clowise(2); 85 Clowise(4); 86 Clowise(5); 87 Clowise(6); 88 Clowise(1); 89 Rev_Clowise(4); 90 } 91 92 inline void Oper3() 93 { 94 swap(sid1[4], sid1[1]); 95 swap(sid1[3], sid1[4]); 96 swap(sid1[2], sid1[3]); 97 98 Clowise(5); 99 Rev_Clowise(6); 100 } 101 102 inline bool Whirling() 103 { 104 for (int a1 = 0; a1 < 4; a1++) 105 { 106 Oper1(); 107 for (int b1 = 0; b1 < 4; b1++) 108 { 109 Oper2(); 110 for (int c1 = 0; c1 < 4; c1++) 111 { 112 Oper3(); 113 if (check()) return true; 114 } 115 } 116 } 117 118 for (int a1 = 0; a1 < 4; a1++) 119 { 120 Oper1(); 121 for (int b1 = 0; b1 < 4; b1++) 122 { 123 Oper3(); 124 for (int c1 = 0; c1 < 4; c1++) 125 { 126 Oper2(); 127 if (check()) return true; 128 } 129 } 130 } 131 132 for (int a1 = 0; a1 < 4; a1++) 133 { 134 Oper2(); 135 for (int b1 = 0; b1 < 4; b1++) 136 { 137 Oper1(); 138 for (int c1 = 0; c1 < 4; c1++) 139 { 140 Oper3(); 141 if (check()) return true; 142 } 143 } 144 } 145 146 for (int a1 = 0; a1 < 4; a1++) 147 { 148 Oper2(); 149 for (int b1 = 0; b1 < 4; b1++) 150 { 151 Oper3(); 152 for (int c1 = 0; c1 < 4; c1++) 153 { 154 Oper1(); 155 if (check()) return true; 156 } 157 } 158 } 159 160 for (int a1 = 0; a1 < 4; a1++) 161 { 162 Oper3(); 163 for (int b1 = 0; b1 < 4; b1++) 164 { 165 Oper1(); 166 for (int c1 = 0; c1 < 4; c1++) 167 { 168 Oper2(); 169 if (check()) return true; 170 } 171 } 172 } 173 174 for (int a1 = 0; a1 < 4; a1++) 175 { 176 Oper3(); 177 for (int b1 = 0; b1 < 4; b1++) 178 { 179 Oper2(); 180 for (int c1 = 0; c1 < 4; c1++) 181 { 182 Oper1(); 183 if (check()) return true; 184 } 185 } 186 } 187 return false; 188 } 189 190 int main() 191 { 192 int T = read(); 193 while (T--) 194 { 195 int a[10]; 196 for (int i = 1; i <= 8; i++) a[i] = read(); 197 Stru(a, sid1); 198 for (int i = 1; i <= 8; i++) a[i] = read(); 199 Stru(a, ned); 200 201 for (int i = 1; i <= 6; i++) Whi(sid1[i]); 202 203 bool flag = false; 204 for (int a1 = 0; a1 < 2; a1++) 205 { 206 if (a1) swap(sid1[1], sid1[3]); 207 for (int b1 = 0; b1 < 2; b1++) 208 { 209 if (b1) swap(sid1[2], sid1[4]); 210 for (int c1 = 0; c1 < 2; c1++) 211 { 212 if (c1) swap(sid1[5], sid1[6]); 213 if (Whirling()) { flag = true; break; } 214 if (c1) swap(sid1[5], sid1[6]); 215 } 216 if (flag) break; 217 if (b1) swap(sid1[2], sid1[4]); 218 } 219 if (flag) break; 220 if (a1) swap(sid1[1], sid1[3]); 221 } 222 if (flag) puts("yes"); 223 else puts("no"); 224 } 225 return 0; 226 }
总结：
一切正常，没啥说的
