[coding horror] 1 - sum 2

sum 2

描述

输入一个递增排序的数组和一个数字S，在数组中查找两个数，是的他们的和正好是S，如果有多对数字的和等于S，输出两个数的乘积最小的。

对应每个测试案例，输出两个数，小的先输出。

coding horror

class Solution {
public:
    vector<int> FindNumbersWithSum(vector<int> array,int sum) {
     	vector<int> ret;

    	if(array.size()==0){
    		return ret;
    	};

     	vector<int> first_nums;
     	vector<int> second_nums;

     	int first_index = 0;
     	int second_index = array.size() - 1;

     	while(first_index < second_index){ // index越界
     		int first = array[first_index];
     		int second = array[second_index];

     		if( first + second == sum) {
     			first_nums.push_back(first);
     			second_nums.push_back(second);
     			first_index++;
     			second_index--;
     		}
     		else if(first + second < sum){
     			first_index++;
     		}
     		else{ // first + second > sum
     			second_index--;
     		}
     	}

     	int min_index = 0;
     	int min; // 未初始化最小值
     	for(int i =0 ;i < first_nums.size(); i++){
     		if(first_nums[i]*second_nums[i] < min){
     			min_index = i;
     			min = first_nums[i]*second_nums[i];
     		}
     	}

     	ret.push_back(first_nums[min_index]);
     	ret.push_back(second_nums[min_index]);

     	return ret;
    }
};

maybe ok

#include "stdio.h"
#include <vector>

using std::vector;

class Solution {
public:
    vector<int> FindNumbersWithSum(vector<int> array,int sum) {
     	vector<int> ret;

    	if(array.size()==0){
    		return ret;
    	};

     	vector<int> first_nums;
     	vector<int> second_nums;

     	int first_index = 0;
     	int second_index = array.size() - 1;

     	while((first_index < second_index)&&(first_index <array.size()-1)&&(second_index>0)){// 注意索引不要越界。
     		int first = array[first_index];
     		int second = array[second_index];

     		if( first + second == sum) {
     			first_nums.push_back(first);
     			second_nums.push_back(second);
     			first_index++;
     			second_index--;
     		}
     		else if(first + second < sum){
     			first_index++;
     		}
     		else{ // first + second > sum
     			second_index--;
     		}
     	}

        if(first_nums.size()>0){
            int min_index = 0;
            int min = first_nums[0]*second_nums[0];// 1.如果vector为空可能造成越界，需先判断vector是否为空。2. 用于比较的最小值要先赋初始值。

            for(int i =0 ;i < first_nums.size(); i++){
                if(first_nums[i]*second_nums[i] < min){
                    min_index = i;
                    min = first_nums[i]*second_nums[i];
                }
            }

            ret.push_back(first_nums[min_index]);
            ret.push_back(second_nums[min_index]);
        }

     	return ret;
    }
};

int main(int argc, char const *argv[])
{
    /* code */
    int nums[] = {1,1,1,3,1};
    std::vector<int> vnums(nums,nums+5);
    Solution sol;

    std::vector<int> vret;
    vret = sol.FindNumbersWithSum(vnums,5);

    for(std::vector<int>::iterator it= vret.begin(); it != vret.end();it++){
        printf("%d\n", *it);
    }
    return 0;

}