本文概述
- C ++
- Java
- Python3
- C#
- CPP
- C ++
- Java
- C#
列表1
和
list2
包含
米
和
?
项目。每个项目都与两个字段关联:名称和价格。问题是要计算两个列表中价格不同的商品。
例子:
Input : list1[] = {{"apple", 60}, {"bread", 20}, {"wheat", 50}, {"oil", 30}}
list2[] = {{"milk", 20}, {"bread", 15}, {"wheat", 40}, {"apple", 60}}
Output : 2
bread and wheat are the two items common to both the
lists but with different prices.
资源: 认知面试经验|设置5。
推荐:请尝试以下方法
{IDE}
【计算两个列表共有但价格不同的商品】首先, 在继续解决方案之前。
方法1(天真的方法):使用两个嵌套循环比较列表1与的所有项目list2。如果找到价格不同的匹配项, 则递增计数.
C ++
// C++ implementation to count items common to both
// the lists but with different prices
#include <
bits/stdc++.h>
using namespace std;
// details of an item
struct item
{
string name;
int price;
};
// function to count items common to both
// the lists but with different prices
int countItems(item list1[], int m, item list2[], int n)
{
int count = 0;
// for each item of 'list1' check if it is in 'list2'
// but with a different price
for ( int i = 0;
i <
m;
i++)
for ( int j = 0;
j <
n;
j++)
if ((list1[i].name.compare(list2[j].name) == 0) &
&
(list1[i].price != list2[j].price))
count++;
// required count of items
return count;
}
// Driver program to test above
int main()
{
item list1[] = {{ "apple" , 60}, { "bread" , 20}, { "wheat" , 50}, { "oil" , 30}};
item list2[] = {{ "milk" , 20}, { "bread" , 15}, { "wheat" , 40}, { "apple" , 60}};
int m = sizeof (list1) / sizeof (list1[0]);
int n = sizeof (list2) / sizeof (list2[0]);
cout <
<
"Count = "
<
<
countItems(list1, m, list2, n);
return 0;
}
Java
// Java implementation to count items common to both
// the lists but with different prices
class GFG{
// details of an item
static class item
{
String name;
int price;
public item(String name, int price) {
this .name = name;
this .price = price;
}
};
// function to count items common to both
// the lists but with different prices
static int countItems(item list1[], int m, item list2[], int n)
{
int count = 0 ;
// for each item of 'list1' check if it is in 'list2'
// but with a different price
for ( int i = 0 ;
i <
m;
i++)
for ( int j = 0 ;
j <
n;
j++)
if ((list1[i].name.compareTo(list2[j].name) == 0 ) &
&
(list1[i].price != list2[j].price))
count++;
// required count of items
return count;
}
// Driver code
public static void main(String[] args)
{
item list1[] = { new item( "apple" , 60 ), new item( "bread" , 20 ), new item( "wheat" , 50 ), new item( "oil" , 30 )};
item list2[] = { new item( "milk" , 20 ), new item( "bread" , 15 ), new item( "wheat" , 40 ), new item( "apple" , 60 )};
int m = list1.length;
int n = list2.length;
System.out.print( "Count = "
+ countItems(list1, m, list2, n));
}
}
// This code is contributed by 29AjayKumar
Python3
# Python implementation to
# count items common to both
# the lists but with different
# prices
# function to count items
# common to both
# the lists but with different prices
def countItems(list1, list2):
count = 0# for each item of 'list1'
# check if it is in 'list2'
# but with a different price
for i in list1:
for j in list2:
if i[ 0 ] = = j[ 0 ] and i[ 1 ] ! = j[ 1 ]:
count + = 1# required count of items
return count
# Driver program to test above
list1 = [( "apple" , 60 ), ( "bread" , 20 ), ( "wheat" , 50 ), ( "oil" , 30 )]
list2 = [( "milk" , 20 ), ( "bread" , 15 ), ( "wheat" , 40 ), ( "apple" , 60 )]print ( "Count = " , countItems(list1, list2))# This code is contributed by Ansu Kumari.
C#
// C# implementation to count items common to both
// the lists but with different prices
using System;
class GFG{// details of an item
class item
{
public String name;
public int price;
public item(String name, int price) {
this .name = name;
this .price = price;
}
};
// function to count items common to both
// the lists but with different prices
static int countItems(item []list1, int m, item []list2, int n)
{
int count = 0;
// for each item of 'list1' check if it is in 'list2'
// but with a different price
for ( int i = 0;
i <
m;
i++)
for ( int j = 0;
j <
n;
j++)if ((list1[i].name.CompareTo(list2[j].name) == 0) &
&
(list1[i].price != list2[j].price))
count++;
// required count of items
return count;
}// Driver code
public static void Main(String[] args)
{
item []list1 = { new item( "apple" , 60), new item( "bread" , 20), new item( "wheat" , 50), new item( "oil" , 30)};
item []list2 = { new item( "milk" , 20), new item( "bread" , 15), new item( "wheat" , 40), new item( "apple" , 60)};
int m = list1.Length;
int n = list2.Length;
Console.Write( "Count = "
+ countItems(list1, m, list2, n));
}
}
// This code is contributed by PrinciRaj1992
输出如下:
Count = 2
时间复杂度:O(m * n)。
辅助空间:O(1)。
方法2(二分搜索):
排序
list2
按项目名称的字母顺序排列。现在, 对于
列表1
检查它是否存在
list2
使用二进制搜索技术并从中获取价格
list2
。如果价格不同, 则增加
计数
.
CPP
// C++ implementation to count items common to both
// the lists but with different prices
#include <
bits/stdc++.h>
using namespace std;
// details of an item
struct item
{
string name;
int price;
};
// comparator function used for sorting
bool compare( struct item a, struct item b)
{
return (a.name.compare(b.name) <
= 0);
}
// function to search 'str' in 'list2[]'. If it exists then
// price associated with 'str' in 'list2[]' is being
// returned else -1 is returned. Here binary serach
// trechnique is being applied for searching
int binary_search(item list2[], int low, int high, string str)
{
while (low <
= high)
{
int mid = (low + high) / 2;
// if true the item 'str' is in 'list2'
if (list2[mid].name.compare(str) == 0)
return list2[mid].price;
else if (list2[mid].name.compare(str) <
0)
low = mid + 1;
else
high = mid - 1;
}// item 'str' is not in 'list2'
return -1;
}
// function to count items common to both
// the lists but with different prices
int countItems(item list1[], int m, item list2[], int n)
{
// sort 'list2' in alphabetcal order of
// items name
sort(list2, list2 + n, compare);
// initial count
int count = 0;
for ( int i = 0;
i <
m;
i++) {
// get the price of item 'list1[i]' from 'list2'
// if item in not present in second list then
// -1 is being obtained
int r = binary_search(list2, 0, n-1, list1[i].name);
// if item is present in list2 with a
// different price
if ((r != -1) &
&
(r != list1[i].price))
count++;
}// required count of items
return count;
}
// Driver program to test above
int main()
{
item list1[] = {{ "apple" , 60}, { "bread" , 20}, { "wheat" , 50}, { "oil" , 30}};
item list2[] = {{ "milk" , 20}, { "bread" , 15}, { "wheat" , 40}, { "apple" , 60}};
int m = sizeof (list1) / sizeof (list1[0]);
int n = sizeof (list2) / sizeof (list2[0]);
cout <
<
"Count = "
<
<
countItems(list1, m, list2, n);
return 0;
}
输出如下:
Count = 2
时间复杂度:(m * log
2
n)。
辅助空间:O(1)。
为了提高效率, 应对元素数量最大的列表进行排序, 并用于二进制搜索。
方法3(有效方法):
使用创建哈希表
(核心价值)
元组为
(商品名称, 价格)
。插入的元素
列表1
在哈希表中。现在, 对于
list2
检查它是否是哈希表。如果存在, 则检查其价格是否与哈希表中的值不同。如果是这样, 则增加
计数
.
C ++
// C++ implementation to count items common to both
// the lists but with different prices
#include <
bits/stdc++.h>
using namespace std;
// details of an item
struct item
{
string name;
int price;
};
// function to count items common to both
// the lists but with different prices
int countItems(item list1[], int m, item list2[], int n)
{
// 'um' implemented as hash table that contains
// item name as the key and price as the value
// associated with the key
unordered_map<
string, int >
um;
int count = 0;
// insert elements of 'list1' in 'um'
for ( int i = 0;
i <
m;
i++)
um[list1[i].name] = list1[i].price;
// for each element of 'list2' check if it is
// present in 'um' with a different price
// value
for ( int i = 0;
i <
n;
i++)
if ((um.find(list2[i].name) != um.end()) &
&
(um[list2[i].name] != list2[i].price))
count++;
// required count of items
return count;
}
// Driver program to test above
int main()
{
item list1[] = {{ "apple" , 60}, { "bread" , 20}, { "wheat" , 50}, { "oil" , 30}};
item list2[] = {{ "milk" , 20}, { "bread" , 15}, { "wheat" , 40}, { "apple" , 60}};
int m = sizeof (list1) / sizeof (list1[0]);
int n = sizeof (list2) / sizeof (list2[0]);
cout <
<
"Count = "
<
<
countItems(list1, m, list2, n);
return 0;
}
Java
// Java implementation to count
// items common to both the lists
// but with different prices
import java.util.*;
class GFG{
// details of an item
static class item
{
String name;
int price;
public item(String name, int price)
{
this .name = name;
this .price = price;
}
};
// function to count items common to both
// the lists but with different prices
static int countItems(item list1[], int m, item list2[], int n)
{
// 'um' implemented as hash table that contains
// item name as the key and price as the value
// associated with the key
HashMap<
String, Integer>
um = new HashMap<
>
();
int count = 0 ;
// insert elements of 'list1' in 'um'
for ( int i = 0 ;
i <
m;
i++)
um.put(list1[i].name, list1[i].price);
// for each element of 'list2' check if it is
// present in 'um' with a different price
// value
for ( int i = 0 ;
i <
n;
i++)
if ((um.containsKey(list2[i].name)) &
&
(um.get(list2[i].name) != list2[i].price))
count++;
// required count of items
return count;
}
// Driver program to test above
public static void main(String[] args)
{
item list1[] = { new item( "apple" , 60 ), new item( "bread" , 20 ), new item( "wheat" , 50 ), new item( "oil" , 30 )};
item list2[] = { new item( "milk" , 20 ), new item( "bread" , 15 ), new item( "wheat" , 40 ), new item( "apple" , 60 )};
int m = list1.length;
int n = list2.length;
System.out.print( "Count = " +
countItems(list1, m, clist2, n));
}
}
// This code is contributed by gauravrajput1
C#
// C# implementation to count
// items common to both the lists
// but with different prices
using System;
using System.Collections.Generic;
class GFG{
// Details of an item
public class item
{
public String name;
public int price;
public item(String name, int price)
{
this .name = name;
this .price = price;
}
};
// Function to count items common to
// both the lists but with different prices
static int countItems(item []list1, int m, item []list2, int n)
{
// 'um' implemented as hash table
// that contains item name as the
// key and price as the value
// associated with the key
Dictionary<
String, int >
um = new Dictionary<
String, int >
();
int count = 0;
// Insert elements of 'list1'
// in 'um'
for ( int i = 0;
i <
m;
i++)
um.Add(list1[i].name, list1[i].price);
// For each element of 'list2'
// check if it is present in
// 'um' with a different price
// value
for ( int i = 0;
i <
n;
i++)
if ((um.ContainsKey(list2[i].name)) &
&
(um[list2[i].name] != list2[i].price))
count++;
// Required count of items
return count;
}
// Driver code
public static void Main(String[] args)
{
item []list1 = { new item( "apple" , 60), new item( "bread" , 20), new item( "wheat" , 50), new item( "oil" , 30)};
item []list2 = { new item( "milk" , 20), new item( "bread" , 15), new item( "wheat" , 40), new item( "apple" , 60)};
int m = list1.Length;
int n = list2.Length;
Console.Write( "Count = " +
countItems(list1, m, list2, n));
}
}
// This code is contributed by shikhasingrajput
输出如下:
Count = 2
时间复杂度:O(m + n)。
辅助空间:O(m)。
为了提高效率, 应在哈希表中插入元素数量最少的列表。
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