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修订版 1
我看过这个线程：所有可能的毕达哥拉斯三元组
看起来与我的相似，但由于某种原因我无法让我的工作......这是我的代码：

#include <iostream>
#include <cmath>
using namespace std;

class Labb2_uppg1 {
public:
    void run() {
        compute();
    }
private:
void compute() {                                                            // performs the computations
    int a, b, c, counter = 0, counter_pyth = 0;                             // a = cathetus of triangle
                                                                            // b = cathetus of triangle
                                                                            // c = hypotenuse of triangle
                                                                            // counter = used to determine the amount of iterated triangles
                                                                            // counter_pyth = used to determine the subset of pythagorean triangles in the total amount of iterated triangles
    for (a = 1; a <= 500; a++) {
        for (b = a; b <= 500; b++) {                                        // starts from the same index as 'a' to omit duplicate results
            counter++;
            c = int_sqrt((a*a)+(b*b));
            if (c == 100 || c == 200 || c == 300 || c == 400 || c == 500)   // prints the triangles whose hypotenuse matches the integers 100, 200, 300, 400 and 500
                cout << "Triangel med hypotenusan " << c << ": a = " << a << ", b = " << b << endl;
            if (((a*a)+(b*b))==(c*c)) {
                cout << "DEBUG_01: a = " << a << ", b = " << b
                     << ", c = " << c << endl;
                counter_pyth++;
            }
        }
    }
    cout << "\nAntal itererade trianglar: " << counter;                     // prints the number of triangles that the program has iterated through
    cout << "\nAntal pytagoreiska trianglar: " << counter_pyth << "\n\n";   // prints the number of Pythagorean triangles that the program has iterated through
}

int int_sqrt(int r) {                                                       // simplification of the Bakhsali Approximation method to calculate square roots
                                                                            // only integers may be used when invoking this function
                                                                            // returns the integer square root if it was successfully calculated using the radicand r
    int i = 0;                                                              // initiates 'i' to a value of 0
    while ((i*i) <= r)                                                      // approximates the square of 'i' to the radicand 'r'
        i++;
    i--;

    if ((i*i) == r)                                                         // if the square of 'i' is exactly 'r'
        return i;                                                           // then the integer root of 'r' has successfully been found
    else
        return -1;                                                          // else -1 is returned, no real number (radicand) can have -1 as its root
    }

};

输出：

DEBUG_01：a = 95，b = 228，c = 247

DEBUG_01：a = 96，b = 110，c = 146
DEBUG_01：a = 96，b = 128，c = 160
DEBUG_01：a = 96，b = 180 , c = 204
DEBUG_01: a = 96, b = 247, c = 265
DEBUG_01: a = 96, b = 280, c = 296
DEBUG_01: a = 96, b = 378, c = 390
DEBUG_01: a = 98, b = 336, c = 350
DEBUG_01: a = 99, b = 132, c = 165
DEBUG_01: a = 99, b = 168, c = 195
DEBUG_01: a = 99, b = 440, c = 451
DEBUG_01: a = 100 , b = 105, c = 145
DEBUG_01: a = 100, b = 240, c = 260
DEBUG_01: a = 100, b = 495, c = 505
DEBUG_01: a = 102, b = 136, c = 170
DEBUG_01: a = 102，b = 280，c = 298
DEBUG_01：a = 104，b = 153，c = 185
DEBUG_01：a = 104，b = 195，c = 221
DEBUG_01：a = 104，b = 330，c = 346
DEBUG_01：a = 105，b = 140，c = 175
DEBUG_01：a = 105，b = 208，c = 233
DEBUG_01：a = 105，b = 252，c = 273
DEBUG_01：a = 105，b = 360，c = 375
DEBUG_01：a = 108，b = 144，c = 180
DEBUG_01：a = 108，b = 231 , c = 255
DEBUG_01: a = 108, b = 315, c = 333
DEBUG_01: a = 108, b = 480, c = 492
DEBUG_01: a = 110, b = 264, c = 286
DEBUG_01: a = 111, b = 148, c = 185
DEBUG_01: a = 112, b = 180, c = 212
DEBUG_01: a = 112, b = 210, c = 238
Triangel med hypotenusan 400: a = 112, b = 384
DEBUG_01: a = 112, b = 384，c = 400
DEBUG_01：a = 112，b = 441，c = 455
DEBUG_01：a = 114，b = 152，c = 190
DEBUG_01：a = 114，b = 352，c = 370
DEBUG_01：a = 115，b = 252，c = 277
DEBUG_01：a = 115，b = 276，c = 299
DEBUG_01：a = 117，b = 156，c = 195
DEBUG_01：a = 117，b = 240，c = 267
DEBUG_01：a = 119，b = 120，c = 169
DEBUG_01：a = 119，b = 408 , c = 425
DEBUG_01: a = 120, b = 126, c = 174
Triangel med hypotenusan 200: a = 120, b = 160
DEBUG_01: a = 120, b = 160, c = 200
DEBUG_01: a = 120, b = 182, c = 218
DEBUG_01: a = 120, b = 209, c = 241
DEBUG_01: a = 120, b = 225, c = 255
DEBUG_01: a = 120, b = 288, c = 312
DEBUG_01: a = 120, b = 350，c = 370
DEBUG_01：a = 120，b = 391，c = 409
DEBUG_01：a = 120，b = 442，c = 458
DEBUG_01：a = 123，b = 164，c = 205
DEBUG_01：a = 125，b = 300，c = 325
DEBUG_01：a = 126，b = 168，c = 210
DEBUG_01：a = 126，b = 432，c = 450
DEBUG_01：a = 128，b = 240，c = 272
DEBUG_01：a = 129，b = 172，c = 215
DEBUG_01：a = 130，b = 144 , c = 194
DEBUG_01: a = 130, b = 312, c = 338
DEBUG_01: a = 132, b = 176, c = 220
DEBUG_01: a = 132, b = 224, c = 260
DEBUG_01: a = 132, b = 351，c = 375
DEBUG_01：a = 132，b = 385，c = 407
DEBUG_01：a = 132，b = 475，c = 493
DEBUG_01：a = 133，b = 156，c = 205
DEBUG_01：a = 133 , b = 456, c = 475
DEBUG_01: a = 135, b = 180, c = 225
DEBUG_01：a = 135，b = 324，c = 351
DEBUG_01：a = 135，b = 352，c = 377
DEBUG_01：a = 136，b = 255，c = 289
DEBUG_01：a = 136，b = 273，c = 305
DEBUG_01：a = 138，b = 184，c = 230
DEBUG_01：a = 140，b = 147，c = 203
DEBUG_01：a = 140，b = 171，c = 221
DEBUG_01：a = 140，b = 225 , c = 265
DEBUG_01: a = 140, b = 336, c = 364
Triangel med hypotenusan 500: a = 140, b = 480
DEBUG_01: a = 140, b = 480, c = 500
DEBUG_01: a = 141, b = 188，c = 235
DEBUG_01：a = 144，b = 165，c = 219
DEBUG_01：a = 144，b = 192，c = 240
DEBUG_01：a = 144，b = 270，c = 306
DEBUG_01：a = 144， b = 308，c = 340
DEBUG_01：a = 144，b = 420，c = 444
DEBUG_01：a = 145，b = 348，c = 377
DEBUG_01：a = 145，b = 408，c = 433
DEBUG_01：a = 147，b = 196，c = 245
DEBUG_01：a = 150，b = 200，c = 250
DEBUG_01：a = 150，b = 360，c = 390
DEBUG_01：a = 152，b = 285，c = 323
DEBUG_01：a = 152，b = 345，c = 377
DEBUG_01：a = 153，b = 204 , c = 255
DEBUG_01: a = 153, b = 420, c = 447
DEBUG_01: a = 155, b = 372, c = 403
DEBUG_01: a = 155, b = 468, c = 493
DEBUG_01: a = 156, b = 208, c = 260
DEBUG_01: a = 156, b = 320, c = 356
DEBUG_01: a = 156, b = 455, c = 481
DEBUG_01: a = 156, b = 495, c = 519
DEBUG_01: a = 159 , b = 212, c = 265
DEBUG_01: a = 160, b = 168, c = 232
DEBUG_01：a = 160，b = 231，c = 281
DEBUG_01：a = 160，b = 300，c = 340
DEBUG_01：a = 160，b = 384，c = 416
DEBUG_01：a = 161，b = 240，c = 289
DEBUG_01：a = 162，b = 216，c = 270
DEBUG_01：a = 165，b = 220，c = 275
DEBUG_01：a = 165，b = 280，c = 325
DEBUG_01：a = 165，b = 396 , c = 429
DEBUG_01: a = 168, b = 224, c = 280
DEBUG_01: a = 168, b = 270, c = 318
DEBUG_01: a = 168, b = 315, c = 357
DEBUG_01: a = 168, b = 374，c = 410
DEBUG_01：a = 168，b = 425，c = 457
DEBUG_01：a = 168，b = 490，c = 518
DEBUG_01：a = 170，b = 264，c = 314
DEBUG_01：a = 170 , b = 408, c = 442
DEBUG_01: a = 171, b = 228, c = 285
DEBUG_01：a = 174，b = 232，c = 290
DEBUG_01：a = 175，b = 288，c = 337
DEBUG_01：a = 175，b = 420，c = 455
DEBUG_01：a = 176，b = 210，c = 274
DEBUG_01：a = 176，b = 330，c = 374
Triangel med hypotenusan 500：a = 176，b = 468
DEBUG_01：a = 176，b = 468，c = 500
DEBUG_01：a = 177，b = 236， c = 295
DEBUG_01：a = 180，b = 189，c = 261
Triangel med hypotenusan 300：a = 180，b = 240
DEBUG_01：a = 180，b = 240，c = 300
DEBUG_01：a = 180，b = 273 , c = 327
DEBUG_01: a = 180, b = 299, c = 349
DEBUG_01: a = 180, b = 385, c = 425
DEBUG_01: a = 180, b = 432, c = 468
DEBUG_01: a = 183, b = 244，c = 305
DEBUG_01：a = 184，b = 345，c = 391
DEBUG_01：a = 185，b = 444，c = 481
DEBUG_01：a = 186，b = 248，c = 310
DEBUG_01：a = 189，b = 252，c = 315
DEBUG_01：a = 189，b = 340，c = 389
DEBUG_01：a = 190，b = 336，c = 386
DEBUG_01：a = 190，b = 456，c = 494
DEBUG_01：a = 192，b = 220，c = 292
DEBUG_01：a = 192，b = 256 , c = 320
DEBUG_01: a = 192, b = 360, c = 408
DEBUG_01: a = 192, b = 494, c = 530
DEBUG_01: a = 195, b = 216, c = 291
DEBUG_01: a = 195, b = 260, c = 325
DEBUG_01: a = 195, b = 400, c = 445
DEBUG_01: a = 195, b = 468, c = 507
DEBUG_01: a = 196, b = 315, c = 371
DEBUG_01: a = 198 , b = 264, c = 330
DEBUG_01: a = 198, b = 336, c = 390
DEBUG_01：a = 200，b = 210，c = 290
DEBUG_01：a = 200，b = 375，c = 425
DEBUG_01：a = 200，b = 480，c = 520
DEBUG_01：a = 201，b = 268，c = 335
DEBUG_01：a = 203，b = 396，c = 445
DEBUG_01：a = 204，b = 253，c = 325
DEBUG_01：a = 204，b = 272，c = 340
DEBUG_01：a = 205，b = 492 , c = 533
DEBUG_01: a = 207, b = 224, c = 305
DEBUG_01: a = 207, b = 276, c = 345
DEBUG_01: a = 208, b = 306, c = 370
DEBUG_01: a = 208, b = 390, c = 442
DEBUG_01: a = 210, b = 280, c = 350
DEBUG_01: a = 210, b = 416, c = 466
DEBUG_01: a = 213, b = 284, c = 355
DEBUG_01: a = 216 , b = 288, c = 360
DEBUG_01: a = 216, b = 405, c = 459
DEBUG_01：a = 216，b = 462，c = 510
DEBUG_01：a = 217，b = 456，c = 505
DEBUG_01：a = 219，b = 292，c = 365
DEBUG_01：a = 220，b = 231，c = 319
DEBUG_01：a = 220，b = 459，c = 509
DEBUG_01：a = 222，b = 296，c = 370
DEBUG_01：a = 224，b = 360，c = 424
DEBUG_01：a = 224，b = 420 , c = 476
DEBUG_01: a = 225, b = 272, c = 353
DEBUG_01: a = 225, b = 300, c = 375
DEBUG_01: a = 228, b = 304, c = 380
DEBUG_01: a = 228, b = 325, c = 397
DEBUG_01: a = 231, b = 308, c = 385
DEBUG_01: a = 231, b = 392, c = 455
DEBUG_01: a = 232, b = 435, c = 493
DEBUG_01: a = 234 , b = 312, c = 390
DEBUG_01: a = 234, b = 480, c = 534
DEBUG_01：a = 237，b = 316，c = 395
DEBUG_01：a = 238，b = 240，c = 338
DEBUG_01：a = 240，b = 252，c = 348
DEBUG_01：a = 240，b = 275，c = 365
Triangel med hypotenusan 400：a = 240，b = 320
DEBUG_01：a = 240，b = 320，c = 400
DEBUG_01：a = 240，b = 364，c = 436
DEBUG_01：a = 240，b = 418， c = 482
DEBUG_01：a = 240，b = 450，c = 510
DEBUG_01：a = 243，b = 324，c = 405
DEBUG_01：a = 246，b = 328，c = 410
DEBUG_01：a = 248，b = 465，c = 527
DEBUG_01：a = 249，b = 332，c = 415
DEBUG_01：a = 252，b = 275，c = 373
DEBUG_01：a = 252，b = 336，c = 420
DEBUG_01：a = 252， b = 405，c = 477
DEBUG_01：a = 255，b = 340，c = 425
DEBUG_01：a = 255，b = 396，c = 471
DEBUG_01：a = 256，b = 480，c = 544
DEBUG_01：a = 258，b = 344，c = 430
DEBUG_01：a = 260，b = 273，c = 377
DEBUG_01：a = 260，b = 288，c = 388
DEBUG_01：a = 261，b = 348，c = 435
DEBUG_01：a = 261，b = 380，c = 461
DEBUG_01：a = 264，b = 315 , c = 411
DEBUG_01: a = 264, b = 352, c = 440
DEBUG_01: a = 264, b = 448, c = 520
DEBUG_01: a = 264, b = 495, c = 561
DEBUG_01: a = 266, b = 312，c = 410
DEBUG_01：a = 267，b = 356，c = 445
DEBUG_01：a = 270，b = 360，c = 450
DEBUG_01：a = 273，b = 364，c = 455
DEBUG_01：a = 276 , b = 368, c = 460
DEBUG_01: a = 276, b = 493, c = 565
DEBUG_01：a = 279，b = 372，c = 465
DEBUG_01：a = 279，b = 440，c = 521
DEBUG_01：a = 280，b = 294，c = 406
DEBUG_01：a = 280，b = 342，c = 442
DEBUG_01：a = 280，b = 351，c = 449
DEBUG_01：a = 280，b = 450，c = 530
DEBUG_01：a = 282，b = 376，c = 470
DEBUG_01：a = 285，b = 380 , c = 475
DEBUG_01: a = 288, b = 330, c = 438
DEBUG_01: a = 288, b = 384, c = 480
DEBUG_01: a = 291, b = 388, c = 485
DEBUG_01: a = 294, b = 392，c = 490
DEBUG_01：a = 297，b = 304，c = 425
DEBUG_01：a = 297，b = 396，c = 495
DEBUG_01：a = 300，b = 315，c = 435
Triangel med hypotenusan 500： a = 300，b = 400
DEBUG_01：a = 300，b = 400，c = 500
DEBUG_01：a = 300，b = 455，c = 545
DEBUG_01：a = 303，b = 404，c = 505
DEBUG_01：a = 306，b = 408，c = 510
DEBUG_01：a = 308，b = 435，c = 533
DEBUG_01：a = 308，b = 495，c = 583
DEBUG_01：a = 309，b = 412，c = 515
DEBUG_01：a = 312，b = 416，c = 520
DEBUG_01：a = 312，b = 459 , c = 555
DEBUG_01: a = 315, b = 420, c = 525
DEBUG_01: a = 318, b = 424, c = 530
DEBUG_01: a = 319, b = 360, c = 481
DEBUG_01: a = 320, b = 336，c = 464
DEBUG_01：a = 320，b = 462，c = 562
DEBUG_01：a = 321，b = 428，c = 535
DEBUG_01：a = 322，b = 480，c = 578
DEBUG_01：a = 324 , b = 432, c = 540
DEBUG_01: a = 325, b = 360, c = 485
DEBUG_01：a = 327，b = 436，c = 545
DEBUG_01：a = 330，b = 440，c = 550
DEBUG_01：a = 333，b = 444，c = 555
DEBUG_01：a = 336，b = 377，c = 505
DEBUG_01：a = 336，b = 385，c = 511
DEBUG_01：a = 336，b = 448，c = 560
DEBUG_01：a = 339，b = 452，c = 565
DEBUG_01：a = 340，b = 357 , c = 493
DEBUG_01: a = 341, b = 420, c = 541
DEBUG_01: a = 342, b = 456, c = 570
DEBUG_01: a = 345, b = 460, c = 575
DEBUG_01: a = 348, b = 464，c = 580
DEBUG_01：a = 351，b = 468，c = 585
DEBUG_01：a = 352，b = 420，c = 548
DEBUG_01：a = 354，b = 472，c = 590
DEBUG_01：a = 357 , b = 360, c = 507
DEBUG_01: a = 357, b = 476, c = 595
DEBUG_01：a = 360，b = 378，c = 522
DEBUG_01：a = 360，b = 480，c = 600
DEBUG_01：a = 363，b = 484，c = 605
DEBUG_01：a = 366，b = 488，c = 610
DEBUG_01：a = 368，b = 465，c = 593
DEBUG_01：a = 369，b = 492，c = 615
DEBUG_01：a = 372，b = 496，c = 620
DEBUG_01：a = 375，b = 500 , c = 625
DEBUG_01: a = 380, b = 399, c = 551
DEBUG_01: a = 384, b = 440, c = 584
DEBUG_01: a = 390, b = 432, c = 582
DEBUG_01: a = 396, b = 403，c = 565
DEBUG_01：a = 399，b = 468，c = 615
DEBUG_01：a = 400，b = 420，c = 580
DEBUG_01：a = 414，b = 448，c = 610
DEBUG_01：a = 420 , b = 441, c = 609
DEBUG_01: a = 429, b = 460, c = 629
DEBUG_01：a = 432，b = 495，c = 657
DEBUG_01：a = 440，b = 462，c = 638
DEBUG_01：a = 460，b = 483，c = 667
DEBUG_01：a = 476，b = 480，c = 676

Antal itererade 三角：125250 Antal pytagoreiska 三角：456

如您所见，每当我运行此程序时，我都会从“counter_pyth”中得到答案“456”，根据我的老师的说法，正确答案是“386”，但我不知道我做错了什么..

修订版 2

代码：

.
.
.

for (a = 1; a <= 500; a++) {
        for (b = a; b <= 500; b++) {                                        // starts from the same index as 'a' to omit duplicate results
            counter++;
            c = int_sqrt((a*a)+(b*b));
            if (c == 100 || c == 200 || c == 300 || c == 400 || c == 500)   // prints the triangles whose hypotenuse matches the integers 100, 200, 300, 400 and 500
                cout << "Triangel med hypotenusan " << c << ": a = " << a << ", b = " << b << endl;
            if (((a*a)+(b*b))==(c*c)) {
                if (!((a > 500 ) || (b > 500) || (c > 500))) {
                    cout << "DEBUG_01: a = " << a << ", b = " << b
                    << ", c = " << c << endl;
                    counter_pyth++;
                }
            }
        }
    }
4

1 回答 1

1

（与您链接的问题一起）尝试c改为计数，因为c必须最多为 500，并且对aor没有限制b：

for(int c = 1; c <= 500; c++) {
    for(int a = 1; a < c; a++) {
        int b = int_sqrt(c * c - a * a);
        if(b > 0) {
            //you've found a right triangle with c at most 500
        }
    }
}

您可能计算了超过 386 个三角形，因为您计算的是c > 500.

于 2012-12-08T18:01:14.313 回答