Question

我正在做一个家庭作业，它应该打印总和为val的所有整数对。我到目前为止已完成，除了它打印重复值（即（3,1）和（1,3）的值添加到4）。如何删除这些重复的值对？

#include <iostream>
#include <map>
#include <vector>

using namespace std;

void printPairs( vector<int> numbers, int val){
    int i;
    int temp;

    map<int,int>valMap;
    for(i = 0; i < numbers.size(); i++){
      temp = val - numbers[i];
      if(temp >= 0 && valMap[temp] == 1){

        printf("Pair of integers that sum to val %d is (%d, %d) \n", val,                    numbers[i], temp);  

}
        valMap[numbers[i]] = 1;
}

}

int main(int argc, char *argv[]) {

    vector <int> v(11);
    v[0]=1;
    v[1]=2;
    v[2]=3;
    v[3]=4;
    v[4]=5;
    v[5]=6;
    v[6]=7;
    v[7]=1;
    v[8]=2;
    v[9]=3;
    v[10]=4;


    printPairs(v,7);



    system("PAUSE");
}

Answer 1

这种打印功能的变种......

void printPairs( vector<int> numbers, int val){
    int i, j;
    map<int,int>valMap;
    // build a map
    for(i = 0; i < numbers.size() - 1; i++)
    {
        for(j = i; j < numbers.size(); j++)
        {
            if( (numbers[i] + numbers[j]) == val)
            {
                // use minimum value as a key, and max value as a value
                valMap[ (numbers[i] < numbers[j])?numbers[i]:numbers[j] ] = (numbers[i] >= numbers[j])?numbers[i]:numbers[j];
            }
        }
    }
    // print all map's values
    for(map<int,int>::iterator iter = valMap.begin(); iter !=valMap.end(); iter++)
    {
        printf("Pair of integers that sum to val %d is (%d, %d) \n", val, iter->first, iter->second);
    }
}

...给出输出......

Pair of integers that sum to val 7 is (1, 6)
Pair of integers that sum to val 7 is (2, 5)
Pair of integers that sum to val 7 is (3, 4)

如何使用map删除重复项

1 个答案: