标签：
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:
For example,
Consider the following matrix:
[ [1, 3, 5, 7], [10, 11, 16, 20], [23, 30, 34, 50] ]
Given target = 3, return true.
Array Binary Search
#include<iostream> #include<vector> using namespace std; class Solution { public: bool searchMatrix(vector<vector<int> > &matrix, int target) { int m=matrix.size(); if(m<1) return false; int n=matrix[0].size(); int tm; //cout<<"m:"<<m<<" n:"<<n<<endl; if(m==1) tm=0; else{ if(matrix[m-1][0]<=target) tm=m-1; else{ int lft=0,rgt=m-1; tm =0; do{ if(matrix[tm+1][0]>target) break; int mid = (lft+rgt)/2; if(matrix[mid][0]>target) rgt=mid; else lft=mid; tm = lft; }while(lft+1<rgt); } } int lft=0,rgt=n-1; if(matrix[tm][rgt]==target||matrix[tm][lft]==target) return true; if(matrix[tm][rgt]<target) return false; int tn=lft; do{ int mid=(lft+rgt)/2; if(matrix[tm][mid]>target) rgt = mid; else lft=mid; tn = lft; if(matrix[tm][tn]==target) return true; }while(lft+1<rgt); return false; } }; int main() { vector<vector<int> > matrix{{1, 3, 5, 7},{10, 11, 16, 20},{23, 30, 34, 50}}; Solution sol; cout<<sol.searchMatrix(matrix,2)<<endl; return 0; }
标签：
原文地址：http://www.cnblogs.com/Azhu/p/4202415.html
