1237 LeetCode 找出给定方程的正整数解

题目描述：
LeetCode 第1237题 找出给定方程的正整数解
类型简单

思路：
以1为下限，z为上线遍历查找

代码如下：

/*
 * // This is the custom function interface.
 * // You should not implement it, or speculate about its implementation
 * class CustomFunction {
 * public:
 *     // Returns f(x, y) for any given positive integers x and y.
 *     // Note that f(x, y) is increasing with respect to both x and y.
 *     // i.e. f(x, y) < f(x + 1, y), f(x, y) < f(x, y + 1)
 *     int f(int x, int y);
 * };
 */

class Solution {
public:
    vector<vector<int>> findSolution(CustomFunction& customfunction, int z) {
        vector<int>temp={0,0};
        vector<vector<int>>res;
        int x=1,y=z;
        int cur=z;
        while(x<=z){
            if(customfunction.f(x,y)==z){
                cur=y;
                temp[0]=x;
                temp[1]=y;
                res.push_back(temp);
                x++;
            }
            else {
                y--;
                if(y<1){
                y=cur;
                x++;}
            }
        }
        return res;
    }
};