大数模板（加减乘除幂次开方）
Posted romalzhih
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很好用的模板，但当时做题的时候从哪里找的不知道了，原作看到知会我一声我补上hhh
1 struct BigInteger 2 { 3 int len; 4 int arg[500]; 5 BigInteger(int x = 0) { 6 IntToBigInteger(x); 7 } 8 9 BigInteger(char *str) { 10 CharToBigInteger(str); 11 } 12 void print() 13 { 14 for (int i = len - 1; i >= 0; i--) { 15 cout << arg[i]; 16 } 17 cout << endl; 18 } 19 void CharToBigInteger(char *str) 20 { 21 len = strlen(str); 22 memset(arg, 0, sizeof(arg)); 23 for (int i = 0; i < len; i++) { 24 arg[i] = str[len - i - 1] - 48; 25 } 26 while (len > 0 && arg[len - 1] == 0) { 27 len--; 28 } 29 } 30 void IntToBigInteger(int x) 31 { 32 len = 0; 33 memset(arg, 0, sizeof(arg)); 34 do { 35 arg[len++] = x % 10; 36 x = x / 10; 37 } while (x); 38 } 39 friend istream &operator>>(istream &in, BigInteger &w) 40 { 41 char str[1005]; 42 in >> str; 43 w.CharToBigInteger(str); 44 return in; 45 } 46 friend ostream& operator<<(ostream &out, BigInteger w) 47 { 48 for (int i = w.len - 1; i >= 0; i--) { 49 out << w.arg[i]; 50 } 51 return out; 52 } 53 friend bool operator==(BigInteger r, BigInteger w) 54 { 55 if (r.len != w.len) return false; 56 int i = r.len - 1; 57 while (i >= 0) { 58 if (r.arg[i] != w.arg[i]) 59 return false; 60 i--; 61 } 62 return true; 63 } 64 friend bool operator<=(BigInteger r, BigInteger w) 65 { 66 if (r.len < w.len) return true; 67 else if (w.len < r.len) return false; 68 int i = r.len - 1; 69 while (i >= 0) { 70 if (r.arg[i] < w.arg[i]) 71 return true; 72 else if (r.arg[i] > w.arg[i]) 73 return false; 74 i--; 75 } 76 return true; 77 } 78 friend bool operator<=(int x, BigInteger w) 79 { 80 BigInteger r; 81 r.IntToBigInteger(x); 82 if (r.len < w.len) return true; 83 else if (w.len < r.len) return false; 84 int i = r.len - 1; 85 while (i >= 0) { 86 if (r.arg[i] < w.arg[i]) 87 return true; 88 else if (r.arg[i] > w.arg[i]) 89 return false; 90 i--; 91 } 92 return true; 93 } 94 friend bool operator<(BigInteger r, BigInteger w) 95 { 96 if (r.len < w.len) return true; 97 else if (w.len < r.len) return false; 98 int i = r.len - 1; 99 while (i >= 0) { 100 if (r.arg[i] < w.arg[i]) 101 return true; 102 else if (r.arg[i] > w.arg[i]) 103 return false; 104 i--; 105 } 106 return false; 107 } 108 friend bool operator<(int x, BigInteger w) 109 { 110 BigInteger r; 111 r.IntToBigInteger(x); 112 if (r.len < w.len) return true; 113 else if (w.len < r.len) return false; 114 int i = r.len - 1; 115 while (i >= 0) { 116 if (r.arg[i] < w.arg[i]) 117 return true; 118 else if (r.arg[i] > w.arg[i]) 119 return false; 120 i--; 121 } 122 return false; 123 } 124 friend BigInteger operator+(int r, BigInteger w) { 125 w.arg[0] += r; 126 int i = 0; 127 while (w.arg[i] >= 10) { 128 w.arg[i + 1] += w.arg[i] / 10; 129 w.arg[i] = w.arg[i] % 10; 130 i++; 131 } 132 if (w.arg[i]) i++; 133 w.len = i > w.len ? i : w.len; 134 return w; 135 } 136 friend BigInteger operator+(BigInteger w, int r) 137 { 138 w.arg[0] += r; 139 int i = 0; 140 while (w.arg[i] >= 10) { 141 w.arg[i + 1] += w.arg[i] / 10; 142 w.arg[i] = w.arg[i] % 10; 143 i++; 144 } 145 if (w.arg[i]) i++; 146 w.len = i > w.len ? i : w.len; 147 return w; 148 } 149 friend BigInteger operator+(BigInteger r, BigInteger w) 150 { 151 int len = r.len > w.len ? r.len : w.len; 152 for (int i = 0; i < len; i++) { 153 if (i < w.len) 154 r.arg[i] = r.arg[i] + w.arg[i]; 155 r.arg[i + 1] += r.arg[i] / 10; 156 r.arg[i] = r.arg[i] % 10; 157 } 158 while (r.arg[len] >= 10) { 159 r.arg[len + 1] += r.arg[len] / 10; 160 r.arg[len] = r.arg[len] % 10; 161 len++; 162 } 163 if (r.arg[len]) len++; 164 r.len = len > r.len ? len : r.len; 165 return r; 166 } 167 friend BigInteger operator-(BigInteger r, BigInteger w) 168 { 169 for (int i = 0; i < r.len; i++) { 170 if (r.arg[i] >= w.arg[i]) 171 r.arg[i] = r.arg[i] - w.arg[i]; 172 else { 173 r.arg[i] = r.arg[i] + 10; 174 r.arg[i + 1] = r.arg[i + 1] - 1; 175 r.arg[i] = r.arg[i] - w.arg[i]; 176 } 177 } 178 while (r.arg[r.len - 1] == 0 && r.len > 1) 179 r.len--; 180 return r; 181 } 182 friend BigInteger operator-(BigInteger r, int w) 183 { 184 for (int i = 0; i < r.len; i++, w = w / 10) { 185 if (r.arg[i] >= w % 10) 186 r.arg[i] = r.arg[i] - w % 10; 187 else { 188 r.arg[i] = r.arg[i] + 10; 189 r.arg[i + 1] = r.arg[i + 1] - 1; 190 r.arg[i] = r.arg[i] - w % 10; 191 } 192 } 193 while (r.arg[r.len - 1] == 0 && r.len > 1) 194 r.len--; 195 return r; 196 } 197 friend BigInteger operator*(int x, BigInteger w) 198 { 199 BigInteger r; 200 if (x == 0 || (w.len == 1 && w.arg[0] == 0)) { 201 return r; 202 } 203 for (int i = 0; i < w.len; i++) { 204 r.arg[i] += w.arg[i] * x; 205 r.arg[i + 1] += r.arg[i] / 10; 206 r.arg[i] = r.arg[i] % 10; 207 } 208 int i = r.arg[w.len] == 0 ? w.len - 1 : w.len; 209 while (r.arg[i] >= 10) { 210 r.arg[i + 1] = r.arg[i] / 10; 211 r.arg[i] = r.arg[i] % 10; 212 i++; 213 } 214 r.len = (i >= 0) ? i + 1 : 1; 215 return r; 216 } 217 friend BigInteger operator*(BigInteger w, int x) 218 { 219 BigInteger r; 220 if (x == 0 || (w.len == 1 && w.arg[0] == 0)) { 221 return r; 222 } 223 for (int i = 0; i < w.len; i++) { 224 r.arg[i] += w.arg[i] * x; 225 r.arg[i + 1] += r.arg[i] / 10; 226 r.arg[i] = r.arg[i] % 10; 227 } 228 int i = r.arg[w.len] == 0 ? w.len - 1 : w.len; 229 while (r.arg[i] >= 10) { 230 r.arg[i + 1] = r.arg[i] / 10; 231 r.arg[i] = r.arg[i] % 10; 232 i++; 233 } 234 r.len = (i >= 0) ? i + 1 : 1; 235 return r; 236 } 237 friend BigInteger operator*(BigInteger r, BigInteger w) 238 { 239 BigInteger v; 240 if ((r.len == 1 && r.arg[0] == 0) || (w.len == 1 && w.arg[0] == 0)) { 241 return v; 242 } 243 for (int i = 0; i < r.len; i++) { 244 for (int k = 0; k < w.len; k++) { 245 v.arg[i + k] += w.arg[k] * r.arg[i]; 246 v.arg[i + k + 1] += v.arg[i + k] / 10; 247 v.arg[i + k] = v.arg[i + k] % 10; 248 } 249 } 250 int i = w.len + r.len - 1; 251 i = v.arg[i] == 0 ? i - 1 : i; 252 while (v.arg[i] >= 10) { 253 v.arg[i + 1] = v.arg[i] / 10; 254 v.arg[i] = v.arg[i] % 10; 255 i++; 256 } 257 v.len = (i >= 0) ? i + 1 : 1; 258 return v; 259 } 260 261 friend BigInteger operator/(BigInteger r, int w) 262 { 263 BigInteger h, resl; 264 if (w == 0) return h; 265 for (int i = r.len - 1; i >= 0; i--) { 266 resl = 10 * resl; 267 h = r.arg[i] + (10 * h); 268 while (w <= h) { 269 resl = 1 + resl; 270 h = h - w; 271 } 272 } 273 return resl; 274 } 275 friend BigInteger operator/(BigInteger r, BigInteger w) 276 { 277 BigInteger h, resl; 278 if (w.len == 1 && w.arg[0] == 0) return h; 279 for (int i = r.len - 1; i >= 0; i--) { 280 resl = 10 * resl; 281 h = r.arg[i] + (10 * h); 282 while (w <= h) { 283 resl = 1 + resl; 284 h = h - w; 285 } 286 } 287 return resl; 288 } 289 290 friend BigInteger operator%(BigInteger r, BigInteger w) 291 { 292 BigInteger h; 293 if (w.len == 1 && w.arg[0] == 0) return h; 294 for (int i = r.len - 1; i >= 0; i--) { 295 h = r.arg[i] + (10 * h); 296 while (w <= h) { 297 h = h - w; 298 } 299 } 300 return h; 301 } 302 void sqrt() 303 { 304 BigInteger w, r; 305 w.len = r.len = 0; 306 int lens = len - 1; 307 if (len == 1 && arg[0] == 1) 308 return; 309 r.arg[r.len++] = arg[lens--]; 310 if (len % 2 == 0) 311 r = arg[lens--] + 10 * r; 312 while (lens >= -1) { 313 int i = 0; 314 while ((i*(i + 20 * w)) <= r) { 315 i++; 316 } 317 i--; 318 if (i == -1 || (r.len == 1 && r.arg[0] == 1)) 319 i = 0; 320 r = r - (i*(i + 20 * w)); 321 w = i + 10 * w; 322 if (lens >= 0) { 323 r = arg[lens--] + 10 * r; 324 r = arg[lens--] + 10 * r; 325 } 326 else 327 lens -= 2; 328 } 329 *this = w; 330 } 331 };
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