leetcode系列(1)之twoSum

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import java.util.HashMap;
import java.util.Map;

public class TwoSum {
public static void main(String[] args) {
int[] nums = {438, 507, 629, 255, 813, 423, 536, 428, 340, 767, 208, 808, 882, 142, 835, 423, 331,
545, 627, 750, 397, 675, 662, 92, 465, 627, 15, 522, 395, 727, 561, 73, 570, 606, 826, 651, 743, 214, 881, 685, 820,
326, 653, 334, 698, 604, 938, 260, 51, 597, 291, 855, 427, 117, 943, 142, 166, 439, 833, 4, 180, 10, 531, 350, 785,
989, 607, 303, 554, 764, 769, 451, 654, 752, 15, 90, 505, 159, 1, 516, 801, 938, 442, 543, 761, 548, 523, 766, 445, 696,
217, 352, 333, 383, 868, 764, 556, 943, 280, 140, 627, 870, 635, 753, 743, 978, 611, 326, 405, 143, 564, 256, 304, 913, 570, 331,
340, 222, 952, 959, 535, 113, 148, 125, 874, 354, 984, 753, 423, 448, 235, 621, 796, 355, 64, 682, 326, 500, 609, 293, 566, 974, 808,
568, 729, 173, 735, 764, 987, 588, 227, 961, 621, 340, 245, 570, 640, 814, 635, 482, 520, 563, 695, 399, 95, 92, 813, 135, 342, 513, 410,
943, 64, 458, 801, 835, 977, 932, 838, 604, 500, 266, 395, 108, 788, 161, 769, 662, 697, 167, 143, 383, 880, 19, 758, 552, 396, 226, 548, 560,
916, 766, 568, 192, 100, 734, 639, 288, 187, 465, 345, 535, 293, 130, 488, 172, 108, 313, 800, 662, 644, 758, 843, 953, 73, 543, 630, 37, 711,
372, 372, 410, 60, 973, 750, 833, 827, 572, 31, 157, 473, 529, 410, 650, 930, 635, 253, 203, 159, 431, 848, 969, 982, 229, 504, 617, 273, 723, 854, 572, 879,
382, 18, 418, 990, 321, 871, 544, 662, 900, 340, 358, 788, 998, 376, 87, 520, 543, 717, 67, 713, 419, 108, 796, 143, 342, 896, 526, 926, 362, 23, 63, 426, 514,
526, 499, 857, 87, 499, 635, 496, 69, 558, 635, 1, 635, 125, 611, 459, 11, 14, 305, 969, 225, 677, 354, 90, 509, 317, 895, 617, 798, 210, 830, 63, 488, 139, 500, 744, 564,
295, 782, 214, 569, 863, 835, 14, 70, 687, 321, 130, 933, 822, 761, 985, 637, 995, 604, 932, 54, 51, 170, 951, 774, 117, 117, 863, 940, 599, 820, 473, 350, 572, 776, 198, 958, 1, 281, 539, 874, 38, 205, 591, 901, 588, 743, 926, 270, 675, 135, 208, 588, 438, 444, 752, 172, 709, 191, 199, 494, 743, 854, 362, 340, 170, 909, 434, 258, 621, 983, 119, 37, 281, 987, 53, 486, 709, 824, 817, 590, 632, 798, 207, 691, 592, 358, 92, 316, 864, 345, 488, 408, 172, 392, 402, 188, 880, 336, 350, 739, 301, 953, 314, 414, 261, 701, 431, 984, 350, 800, 476, 370, 952, 580, 585, 335, 14, 486, 448, 710, 637, 134, 665, 166, 631, 526, 877, 940, 492, 855, 563, 417, 517, 543, 496, 979, 802, 100, 100, 854, 706, 350, 796, 140, 46, 434, 811, 543, 743, 614, 838, 803, 583, 280, 748, 124, 570, 134, 18, 282, 879, 324, 142, 904, 861, 884, 974, 630, 319, 340, 130, 954, 130, 199, 681, 465, 295, 597, 492, 893, 552, 920, 370, 221, 293, 26, 632, 695, 967, 372, 321, 723, 907, 701, 733, 520, 482, 927, 11, 606, 466, 404, 529, 402, 166, 646, 60, 802, 101, 822, 93, 12, 336, 136, 650, 539, 640, 791, 108, 997, 268, 833, 562, 132, 423, 879, 884, 362, 374, 522, 188, 496, 472, 531, 434, 942, 46, 528, 423, 504, 664, 867, 467, 685, 899, 884, 746, 548, 937, 296, 436, 295, 486, 722, 288, 465, 89, 736, 900, 174, 497, 37, 84, 817, 411, 486, 387, 949, 893, 187, 776, 771, 617, 175, 516, 705, 296, 452, 268, 6, 922, 402, 991, 723, 609, 98, 347, 588, 554, 80, 169, 197, 931, 19, 597, 888, 164, 347, 27, 916, 378, 630, 321, 644, 156, 362, 4, 705, 164, 465, 543, 806, 282, 827, 448, 670, 950, 458, 388, 239, 744, 507, 516, 414, 459, 934, 130, 924, 440, 166, 788, 343, 379, 884, 758, 808, 912, 187, 706, 419, 88, 355, 996, 331, 777, 500, 863, 796, 627, 124, 535, 561, 466, 370, 101, 383, 813, 44};

    int[] sol = twoSum(nums, 929);

    for (int i = 0; i < sol.length; i++) {
        System.out.println(sol[i]);
    }
}


/**
 * 暴力破解两分钟搞定，无任何意义！
 *
 * @param nums
 * @param target
 * @return
 */
public static int[] twoSum(int[] nums, int target) {
    int[] sol = new int[2];
    for (int i = 0; i < nums.length; i++) {
        for (int j = i + 1; j < nums.length; j++) {
            if (nums[j] == target - nums[i]) {
                sol[0] = i;
                sol[1] = j;
            }
        }
    }
    return sol;
}

/**
 * 采用的官方题解中的两遍hash的方法，自己撸一把。
 *
 * @param nums
 * @param target
 * @return
 */
public static int[] twoSum1(int[] nums, int target) {
    Map<Integer, Integer> num = new HashMap<>();
    for (int i = 0; i < nums.length; i++) {
        num.put(nums[i], i);
    }

    for (int i = 0; i < nums.length; i++) {
        int complent = target - nums[i];
        if (num.containsKey(complent) && num.get(complent) != i) {
            return new int[]{i, num.get(complent)};
        }
    }
    return null;
}


// 采用对target进行分解的思路。即如果在数组中一次遍历即可找到target分解的两部分，即为答案，但是样例只通过了一半。不知问题出在哪里。

/*
public int[] twoSum(int[] nums, int target) {
    int[] sol;
    int k = 0;
    sol = new int[2];
    for (int i = 0; i <= target / 2; i++) {
        for (int j = 0; j < nums.length;j++) {
            if (nums[j] == i || nums[j] == target - i) {
                sol[k++] = j;
            }
        }

        if(k==2){
            break;
        }else{
            k= 0;
        }
    }
    return sol;
}
 */

}