数据表记录包含表索引index和数值value（int范围的正整数），请对表索引相同的记录进行合并，即将相同索引的数值进行求和运算，输出按照index值升序进行输出。
提示:
0 <= index <= 11111111
1 <= value <= 100000
[编程题]合并表记录
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n = scanner.nextInt();
HashMap<Integer, Integer> map = new HashMap<>();
for (int i = 0; i < n; i++) {
int index = scanner.nextInt();
int value = scanner.nextInt();
map.put(index, map.getOrDefault(index, 0) + value);
}
// 将map转换为树状结构，以便按照索引排序
List<Map.Entry<Integer, Integer>> sortedEntries = new ArrayList<>
(map.entrySet());
sortedEntries.sort(Map.Entry.comparingByKey());
for (Map.Entry<Integer, Integer> entry : sortedEntries) {
System.out.println(entry.getKey() + " " + entry.getValue());
}
scanner.close();
}
}
发表于 2024-10-18 23:05:31
回复(0)
import java.util.Scanner;
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
Map<Integer,Integer> map = new TreeMap<>();
while (in.hasNextInt()) {
int num = in.nextInt();
for(int i = 0;i < num;i++){
int key = in.nextInt();
int value = in.nextInt();
if(map.keySet().contains(key)){
map.put(key,map.get(key)+value);
}else{
map.put(key,value);
}
}
}
map.keySet().forEach(key ->{
System.out.println(key+" "+map.get(key));
});
}
}
发表于 2024-09-12 13:52:33
回复(0)
import java.util.Scanner;
import java.util.TreeMap;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int count = in.nextInt();
int key;
int value;
TreeMap<Integer,Integer> TreeMap = new TreeMap<>();
for (int i = 1; i <= count; i++ ) {
key=in.nextInt();
value=in.nextInt();
if (TreeMap.get(key)==null) {
TreeMap.put(key,value);
} else {
value=TreeMap.get(key)+value;
TreeMap.put(key,value);
}
}
for (int getKey : TreeMap.keySet()) {
System.out.println(getKey + " " + TreeMap.get(getKey));
}
}
}
发表于 2024-09-11 21:49:43
回复(0)
import java.util.Scanner;
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
while (in.hasNextInt()) { // 注意 while 处理多个 case
int count = in.nextInt();
Map<Integer, Integer> m = new TreeMap<>();
for (int i=0; i<count; i++) {
int index = in.nextInt();
int value = in.nextInt();
if (m.containsKey(index)) {
m.put(index, value + m.get(index));
} else {
m.put(index, value);
}
}
for (Map.Entry<Integer, Integer> entry : m.entrySet()) {
Integer key = entry.getKey();
Integer value = entry.getValue();
System.out.println(key + " " + value);
}
}
}
}
发表于 2024-09-06 15:09:40
回复(0)
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
Map<Integer, Integer> map = new TreeMap<>();
int rows = scanner.nextInt();
for (int i = 0; i < rows; i++) {
int index = scanner.nextInt();
int value = scanner.nextInt();
if (map.containsKey(index)) {
map.put(index, map.get(index) + value);
}else {
map.put(index, value);
}
}
for (Integer index : map.keySet()) {
System.out.println(index + " " + map.get(index));
}
}
}
发表于 2024-07-02 21:27:24
回复(1)
import java.util.Scanner;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
// 注意 hasNext 和 hasNextLine 的区别
int[][] array = null;
int linecnt = 1;
int cnt = Integer.MAX_VALUE;
int index;
int v;
String line;
String[] lineArr;
int fromIndex = 0;
int[] temp;
while (in.hasNextLine()) { // 注意 while 处理多个 case
if (linecnt == 1) {
cnt = in.nextInt();
array = new int[cnt][];
} else {
line = in.nextLine();
if ("".equals(line)) {
continue;
}
lineArr = line.split(" ");
index = Integer.parseInt(lineArr[0]);
if (index > array.length - 1) {
fromIndex = array.length - 1;
} else {
fromIndex = index;
}
v = Integer.parseInt(lineArr[1]);
for (int i = fromIndex; i >= 0; i--) {
temp = array[i];
if (temp == null) {
temp = new int[2];
temp[0] = index;
temp[1] = v;
array[i] = temp;
break;
}
if (temp[0] == index) {
temp[1] = temp[1] + v;
break;
} else {
temp[0] = temp[0] ^ index;
index = temp[0] ^ index;
temp[0] = temp[0] ^ index;
temp[1] = temp[1] ^ v;
v = temp[1] ^ v;
temp[1] = temp[1] ^ v;
}
}
}
if (linecnt > cnt) {
break;
}
linecnt ++;
}
for (int i = 0; i < array.length; i++) {
if (array[i] != null) {
System.out.println(array[i][0] + " " + array[i][1]);
}
}
}
}
发表于 2024-06-19 06:37:22
回复(0)
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
int[][] index = new int[12][1000000];
while(n>0){
int i = in.nextInt();
int v = in.nextInt();
index[i%12][i/12] += v;
n--;
}
for(int i=0;i<=11111111;i++){
if(index[i%12][i/12]!=0){
System.out.println(i+" "+index[i%12][i/12]);
}
}
}
}
发表于 2024-05-23 16:16:28
回复(1)
import java.util.Scanner;
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
while (input.hasNext()) {
int num = input.nextInt();
//定义map树，定义key-value
TreeMap<Integer, Integer> map = new TreeMap();
int index, value;
for (int i = 0; i < num; i++) {
index = input.nextInt();
value = input.nextInt();
//判断index是否已经存在，若存在，value相加，所不存在，向map中添加index，value
if (map.containsKey(index)) {
map.put(index, map.get(index) + value);
} else
map.put(index, value);
}
//输出
for (Map.Entry<Integer, Integer>entry : map.entrySet()) {
System.out.println(entry.getKey() + " " + entry.getValue());
}
}
}
}
发表于 2024-05-15 22:33:44
回复(0)
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
Scanner in2 = new Scanner(System.in);
Map<Integer, Integer> map = new TreeMap<Integer, Integer>();
for (int i = 0; i < n; i++) {
String line = in2.nextLine();
String[] strs = line.split(" ");
Integer a = Integer.valueOf(strs[0]);
Integer b = Integer.valueOf(strs[1]);
map.put(a, map.getOrDefault(a, 0) + b);
}
map.forEach((k, v)->System.out.println(k + " " + v));
}
}
这个题有问题,每行输入用空格隔开,实际则是每个数字输入后回车
发表于 2024-04-26 11:11:19
回复(1)
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
Integer num = in.nextInt();
Map<Integer,Integer> map = new TreeMap<>();
for (int i = 0; i < num; i++) {
if (i == 0) {
map.put(in.nextInt(),in.nextInt());
} else {
Integer one = in.nextInt();
Integer two = in.nextInt();
if (map.containsKey(one)) {
map.put(one,map.get(one) + two);
} else {
map.put(one,two);
}
}
}
for (Integer key : map.keySet()) {
System.out.println(key + " " + map.get(key));
}
}
编辑于 2024-04-22 16:36:57
回复(0)
import java.util.*;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
int n = sc.nextInt();
int index = 0;
int value = 0;
Map<Integer, Integer> map = new HashMap<>();
for (int i = 0; i < n; i++) {
index = sc.nextInt();
value = sc.nextInt();
if (map.containsKey(index)) {
int val = map.get(index);
val += value;
map.put(index, val);
} else {
map.put(index, value);
}
}
Set<Integer> keySet = map.keySet();
Set<Integer> kSet = new TreeSet<>(keySet);
for (Integer key : kSet) {
System.out.println(key + " " + map.get(key));
}
}
}
编辑于 2024-04-15 18:10:41
回复(0)
Scanner in = new Scanner(System.in);
var n = in.nextLine();
var line=Integer.parseInt(n);
if (line<=0||line > 500) {
System.out.println("超过输入范围，0~500");
return;
}
Map<Integer, Integer> map = new TreeMap<>();
for (int i = 0; i < line; i++) {
var str = in.nextLine();
var strArr = str.split(" ");
if (strArr.length != 2) {
System.out.println("输入格式有误");
return;
}
var index = Integer.parseInt(strArr[0]);
var value = Integer.parseInt(strArr[1]);
if (index < 0 || index > 11111111) {
System.out.println("index超过输入范围，0~111111");
}
if (value<0||value>100000){
System.out.println("value超过输入范围，0~100000");
}
if (map.containsKey(index)) {
map.put(index, map.get(index) + value);
} else {
map.put(index, value);
}
}
map.forEach((k, v) -> System.out.println(k + " " + v));
发表于 2024-03-27 10:22:24
回复(1)
import java.util.Scanner;
import java.util.Map;
import java.util.HashMap;
// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
public static void main(String[] args) {
Scanner in = new Scanner(System.in);
int n = in.nextInt();
Map<Integer,Integer> map = new HashMap<>(n);
for(int i=0 ;i<n;i++){
int key = in.nextInt();
int value = in.nextInt();
if(map.containsKey(key)){
map.put(key,map.get(key) + value);
}else {
map.put(key,value);
}
}
for(Integer key : map.keySet()){
System.out.println(key+ " "+map.get(key));
}
}
}
HashMap实例化时，
Map<Integer,Integer> map = new HashMap<>(n);
去掉指定表长的n时，有两例结果通过不了。能解答一下吗？
编辑于 2024-03-18 17:02:17
回复(0)
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