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Search a 2D Matrix.cpp
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Search a 2D Matrix.cpp
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// Search a 2D Matrix
bool searchMatrix(vector<vector<int> > &matrix, int target, int rowBegin, int rowEnd, int colBegin, int colEnd){
if(rowBegin == rowEnd || colBegin == colEnd){
return false;
}
if(rowBegin + 1 != rowEnd){
int rowMid = (rowBegin+rowEnd)/2;
if(matrix[rowMid][0] > target){
return searchMatrix(matrix, target, rowBegin, rowMid, colBegin, colEnd);
}
else if(matrix[rowMid][0] < target){
if(matrix[rowMid][colEnd-1] < target){
return searchMatrix(matrix, target, rowMid+1, rowEnd, colBegin, colEnd);
}
if(matrix[rowMid][colEnd-1] == target){
return true;
}
else{
return searchMatrix(matrix, target, rowMid, rowMid+1, colBegin, colEnd);
}
}
else{
return true;
}
}
else{
if(colBegin + 1 == colEnd){
return matrix[rowBegin][colBegin] == target;
}
int colMid = (colBegin + colEnd)/2;
if(matrix[rowBegin][colMid] > target){
return searchMatrix(matrix, target, rowBegin, rowEnd, colBegin, colMid);
}
else if(matrix[rowBegin][colMid] < target){
return searchMatrix(matrix, target, rowBegin, rowEnd, colMid, colEnd);
}
else{
return true;
}
}
}
bool searchMatrix(vector<vector<int> > &matrix, int target) {
if(matrix.empty()){
return false;
}
int m = matrix.size();
int n = matrix[0].size();
return searchMatrix(matrix, target, 0, m, 0, n);
}