TwoSum.java

import java.util.ArrayList;
import java.util.List;

/**
 * Given an array of integers, return indices of the two numbers such that they add up to a specific target.
 You may assume that each input would have exactly one solution, and you may not use the same element twice.
 Example:
 Given nums = [2, 7, 11, 15], target = 9,
 Because nums[0] + nums[1] = 2 + 7 = 9,
 return [0, 1].
 */
public class TwoSum {
    public int[] twoSum(int[] nums, int target) {
        List list = new ArrayList();
        int[] index = new int[2];
        for(int i = 0;i < nums.length;i++){
            list.add(nums[i]);
        }
        for(int i = 0;i < nums.length;i++){
            int temp = target - nums[i];
            if(list.contains(temp) && (list.indexOf(temp) != i)){
                int k = list.indexOf(temp);
                index[0] = Math.min(i,k);
                index[1] = Math.max(i,k);
            }
        }
        if(index.length == 0)
            throw new IllegalArgumentException("No solution");
        return index;
    }

    public static void main(String[] args) {
        TwoSum twoSum = new TwoSum();
        int[] nums = {876,879,155,291,431,296,592,965,502,173,869,504,258,342,192,478,270,341,811,794,472,625,229,829,122,858,738,481,102,946,305,399,216,752,413,352,271,193,534,508,152,989,154,456,168,510,391,28,317,409,609,532,784,160,696,105,245,231,20,17,81,781,79,816,918,838,123,602,338,997,192,947,388,515,510,441,175,539,708,980,207,336,524,610,3,427,282,84,953,855,117,737,288,371,623,484,738,874,426,202,481,132,499,500,89,786,276,221,857,398,242,639,771,149,758,775,39,836,70,903,193,959,169,851,798,815,755,498,308,70,217,765,504,498,56,547,578,977,882,909,9,874,223,39,429,982,129,712,77,996,43,613,800,810,73,993,763,978,912,255,468,937,987,701,155,347,980,147,698,41,353,178,396,241,71,482,40,593,993,959,193,544,376,752,804,194,800,837,673,261,348,963,918,217,945,271,493,538,203,54,850,753,954,312,584,399,504,62,124,790,542,239,662,410,12,362,798,726,798,780,785,737,280,931,452,643,362,190,975,520,219,330,290,451,22,756,837,787,758,661,75,697,419,485,290,84,401,447,400,311,121,216,574,724,733,496,680,831,736,43,578,201,109,197,125,66,739,339,925,148,381,513,152,305,603,516,979,133,993,430,167,826,526,290,562,559,947,448,903,289,259,221,915,71,879,639,390,588,496,430,778,722,421,821,436,621,959,728,81,117,202,17,408,829,438,970,93,738,838,902,248,128,903,800,567,829,3,407,306,773,71,323,492,305,301,28,220,455,320,478,873,483,521,260,460,342,846,577,874,530,588,965,985,606,410,443,662,81,667,27,912,602,957,822,164,489,942,414,549,991,747,680,498,831,805,89,846,467,909,7,651,250,534,984,587,348,150,329,194,20,519,250,232,224,378,539,83,177,872,130,419,387,654,917,259,447,979,184,965,51,349,422,983,682,172,177,177,484,652,930,495,65,511,318,621,297,803,476,370,826,328,150,354,393,900,340,73,781,70,260,293,862,335,395,51,326,363,78,968,446,565,683,654,767,719,324,2,617,451,56,789,464,119,53,269,369,137,612,54,217,719,823,601,663,310,594,301,636,22,333,351,126,810,812,827,634,441,534,434,967,637,795,335,965,876,778,987,217,451,264,341,566,656,612,413,682,429,161,801,167,309,846,754,541,9,711,707,848,989,580,20,431,163,252,200,54,56,666,425,592,513,230,894,20,260,282,297,129,414,326,577,184,698,620,138,131,236,848,995,879,354,107,67,92,260,531,757,640,305,848,959,416,109,513,769,131,501,197,225,358,67,663,761,742,83,648,230,59,873,231,228,470,503,615,245,258,84,832,132,156,324,27,583,766,676,130,978,306,387,733,592,763,592,487,504,493,139,897,290,432,976,946,24,586,104,648,333,2,359,166,968,990,39,353,376,839,9,75,874,203,762,489,21,14,888,570,449,539,772,919,697,883,278,18,151,113,148,330,158,772,852,93,288,213,299,338,297,862,371,708,815,108,326,115,923,541,144,521,441,99,773,950,519,948,258,328,624,936,681,935,328,70,826,110,153,236,191,222,340,653,918,976,857,184,193,397,39,190,147,763,760,95,917,559,529,680,376,389,215,705,586,205,653,324,960,33,404,888,680,95,263,860,150,683,930,588,9,690,919,745,815,331,425,879,648,398,2,997,865,429,399,264,704,699,333,126,753,565,529,35,520,94,401,552,592,543,864,23,764,763,51,631,348,198,255,73,281,996,371,23,581,84,367,469,604,716,393,942,764,239,502,501,973,438,760,398,158,853,178,348,659,1000,739,296,444,587,528,355,867,615,847,885,160,357,618,959,330,82,182,59,224,355,250,270,447,534,97,590,284,909,406,954,419,909,158,626,818,350,994,609,540,957,152,827,830,386,380,318,580,853,440,789,432,710,955,381,241,930,880,632,750,876,189,662,127,434,38,144,20,424,27,466,538,158,416,508,990,650,698,990,970,663,121,9,713,489,977,530,694,141,930,169,695,305,567,368,777,442,668,746,618,86,592,185,328,772,213,644,440,178,243,774,467,991,455,404,919,197,830,568,661,826,841,695,52,982,515,47,47,198,9,272,425,975,472,9,302,338,470,542,247,492,367,180,708,521,592,58,572,887,670,314,191,280,256,845,971,157,725,862,452,76,200,538,44,324,992,459,196,18,64,147,423,187,191,246,305,973,802,832,436,444,242,979,351,733,459,825,833,691,372,861,617,618,190,57,848,527,56,378,533,308,430,473,701,401,871,790,459,216,983,305,61,391,251,447,661,951,150,28,572,206,299,477,703,301,227,960,866,450,335,337,852,906,956,873,893,867,196,131,456,608,688,840,569,91,922,606,961,906,836,168,838,91,607,186,754,708,477,248,138,211,458,17,509,645,629,816,47,185,661,856,508,984,320,763,297,9,446,970,472,12,386,476,686,940,387,721,546,206,110,349,88,781,150,308,136,809,670,291,767,889,926,999,832,462,706,13,9,753,458,309,984,404,801,366,56,611,38,691,174,670,306,229,12,151,697,415,180,655,418,975,781,40,448,625,775,722,350,163,397,634,102,961,322,354,836,652,877,997,397,957,640,70,467,976,901,792,173,869,248,829,919,89,324,9,639,560,744,890,846,452,197,558,756,988,771,573,494,64,423,348,296,587,327,909,371,24,369,174,132,197,412,142,257,790,770,171,875,724,608,329,256,626,868,22,311,499,933,173,78,631,931,191,132,970,194,778,33,832,75,76,63,271,905,164,970,716,216,828,56,131,898,565,791,47,634,205,118,280,605,896,433,38,39,303,242,746,673,541,759,588,990,586,244,152,586,371,666,361,691,815,658,537,371,482,656,117,316,327,368,657,848,557,761,221,147,673,945,914,976,579,804,405,182,89,429,133,485,939,586,452,20,292,108,747,188,899,293,125,976,573,162,592,880,241,685,191,539,361,430,84,791,903,475,96,388,485,416,583,944,939,987,939,545,474,272,494,664,543,480,812,212,400,728,28,379,410,127,607,59,614,883,509,695,765,533,665,754,848,268,159,678,807,325,125,92,208,216,337,697,778,466,861,22,950,74,804,925,617,159,73,676,712,558,487,711,774,383,817,737,555,811,304,743,27,67,535,426,766,615,102,437,765,291,718,641,951,255,375,442,204,108,455,592,364,457,758,486,593,780,277,789,323,404,473,258,953,318,898,555,390,727,510,783,427,806,92,33,474,858,851,783,12,752,356,942,307,235,397,915,502,939};
        int target = 28;
        int[] index = twoSum.twoSum(nums,target);
        for(int i = 0;i < index.length;i++){
            System.out.print(index[i] + " ");
        }
    }
}