java数据求和

[caesh]

一组数据，例如：
time finishJobs
2004 1
2005 1
2005 1
2005 1
2006 1
2007 1
需要java程序将time一样的数据进行求和，例如：
time finishJobs
2004 1
2005 3
2006 1
2007 1

请达人赐教！！！！

[JadoNet]

用map不行吗？key="200*" value="自己加"

[封师傅]

大致思路：

Map map=new HashMap();
如果 map.get(time)是空，增加map.put(time,finishJobs )
否则，map.put(time,map.get(time)+finishJobs )

[wuxo84]

可用性不是很好啊

public class Test
{
	public static void main( String[] args )
	{
		int[] time = new int[5];
		time[0] = 2004;
		time[1] = 2005;
		time[2] = 2005;
		time[3] = 2006;
		time[4] = 2007;
		int count = 0;

		for( int i=2004; i<2008; i++ )
		{
			for( int j=0; j<time.length; j++ )
			{
				if( time[j] == i )
					count += 1;
			}
			System.out.println( i + ": " + count );
			count = 0;
		}
	}
}

[yibunengjing]

String[] year = new String[]{"2004", "2005", "2005", "2005", "2006", "2007"};
int[] value = {1, 1, 1, 1, 1, 1};
Map map = new HashMap();
for (int i = 0; i < year.length; i++) {
String thisYear = year[i];
int count = value[i];
if (map.containsKey(thisYear)) {
count = Integer.parseInt(map.get(thisYear).toString()) + value[i];
}
map.put(thisYear, count);
}

[yibunengjing]

String[] year = new String[] { "2004", "2005", "2005", "2005", "2006",
				"2007" };
		int[] value = { 1, 1, 1, 1, 1, 1 };
		Map map = new HashMap();
		for (int i = 0; i < year.length; i++) {
			String thisYear = year[i];
			int count = value[i];
			if (map.containsKey(thisYear)) {
				count = Integer.parseInt(map.get(thisYear).toString())
						+ value[i];
			}
			map.put(thisYear, count);
		}

[rain_night]

LZ的 那要求只能实现其中一组key重复的，若有2组重复的就出错，还是楼主自己想办法吧，我的代码态复杂了，仅提供参考

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashMap;

public class MapUsing {
	public static void main(String[] args) {
		Date[] d = new Date[9];
		d[0] = new Date(2004, 1);
		d[1] = new Date(2005, 1);
		d[2] = new Date(2005, 1);
		d[3] = new Date(2005, 1);
		d[4] = new Date(2005, 1);
		d[5] = new Date(2005, 1);
		d[6] = new Date(2006, 1);
		d[7] = new Date(2008, 1);
		d[8] = new Date(2009, 1);
		Arrays.sort(d);
		HashMap<Integer,Integer> value=exChange(d);
		System.out.println("2004 "+value.get(2004));
		System.out.println("2005 "+value.get(2005));
		System.out.println("2006 "+value.get(2006));
		System.out.println("2008 "+value.get(2008));
		System.out.println("2009 "+value.get(2009));
	}

	public static HashMap<Integer, Integer> exChange(Date[] input) {
		int count = 0;
		int i = 0;
		int j = i + 1;
		boolean flag = false;
		HashMap<Integer, Integer> result = new HashMap<Integer, Integer>(10);
		while (i < input.length && j < input.length) {
			if (flag) {
				result.put(input[i].year, (count + 1));
			} else {
				result.put(input[i].year, input[i].count);
			}
			if (input[i].equals(input[j])) {
				count++;
				j++;
				i = j - 1;
				flag = true;
			} else {
				i++;
				j = i + 1;
				flag = false;
			}
			if (flag) {
				result.put(input[i].year, (count + 1));
			} else {
				result.put(input[i].year, input[i].count);
			}

		}
		return result;
	}
}

class Date implements Comparable {
	public int compareTo(Object o) {
		if (this.year > ((Date) o).year) {
			return 1;
		} else if (this.year < ((Date) o).year) {
			return -1;
		}
		return 0;
	}

	public int year, count;

	public Date(int year, int count) {
		this.year = year;
		this.count = count;
	}

	public String toString() {
		return this.year + " " + this.count;
	}

	public boolean equals(Object o) {
		if (this.year == ((Date) o).year) {
			return true;
		}
		return false;
	}
}

[HellMoxi]

键值对,用键验证,相同就把对应的值累加上!!!

[ycyn521]

...

[xiaoyu_air]

放数据库里多好啊.用关键字

distinct

[caesh]

谢谢大家了 分值平分 多谢多谢

[ycyn521]

这个方法不是最好的，但是算法不错，已通过测试！

//已通过测试
public class Test{
	
	
	//打印方法
	public static void print(int[][] a){
		for(int i = 0; i < a.length; i++){
			for(int j = 0; j < a[i].length; j++ ){
				System.out.print(a[i][j] + "   ");
			}
			System.out.println();
		}
	}
	//主算法,新建一个数组,查找重复的同时,把1加上,然后赋值给新的数组
	public static int[][] done(int[][] a){
		
		int[][] b = {{0,0},{0,0},{0,0},{0,0}};
		int m = 0;
		//数组内部比较开始
		for(int i = 0; i < a.length; i++){
			int sum = a[i][1];
			
			if(a[i][0] != 0){
			for(int j = i+1; j < a.length; j++){
				if (a[i][0] == a[j][0]){
					sum += a[j][1];
					a[j][0] = 0;
				}
				
			}
			//向新数组赋值
			b[m][0] = a[i][0];
			b[m][1] = sum;
			m++;
			}
		}
		//返回一个新数组
		return b;
	}
    public static void main( String[] args ){
    	int[][] a = {{2004,1},{2005,1},{2005,1},{2005,1},{2006,1},{2007,1}};
    	print(a);
    	System.out.println("----------计算后的结果--------");
    	print(done(a));     	

    }
}

输出结果为：
2004 1
2005 1
2005 1
2005 1
2006 1
2007 1
----------计算后的结果--------
2004 1
2005 3
2006 1
2007 1