#include <stdio.h>
#include <time.h>
#include <stdlib.h>
#include <iostream>
#include <ostream>
void sparse_matmul_coo(float *A_values,int *A_rowIndex,int *A_colIndex,int A_nonZeroCount,
                       float *B_values,int *B_rowIndex,int *B_colIndex,int B_nonZeroCount,
					   float *C_values,int *C_rowIndex,int *C_colIndex,int C_nonZeroCount){
	int currentIndex=0;
	for(int i=0;i<A_nonZeroCount;i++){
		int rowA=A_rowIndex[i];
		int colA=A_colIndex[i];
		float valueA=A_values[i];
		for(int j=0;j<B_nonZeroCount;j++){
			int rowB=B_rowIndex[j];
		    int colB=B_colIndex[j];
		    float valueB=B_values[j];
		    
		    if(colA==colB){
		    	float product=valueA*valueB;
		    	
		    	int found=0;
		    	for(int k=0;k<currentIndex;k++){
		    		if(C_rowIndex[k]==rowA&&C_colIndex[k]==colB){
		    			C_values[k]+=product;
		    			found=1;
		    			break;
					}
				}
				if(!found){
					C_values[currentIndex]=product;
					C_rowIndex[currentIndex]=rowA;
					C_colIndex[currentIndex]=colB;
					currentIndex++;
				}
			}
		}
	}
	C_nonZeroCount=currentIndex;
}
int main(){
	float A_values[]={1,2,3,4,5};
	int A_rowIndex[]={0,0,1,2,2};
	int A_colIndex[]={0,2,1,0,2};
	int A_nonZeroCount=5;
	
	float B_values[]={6,8,7,9};
	int B_rowIndex[]={0,2,1,2};
	int B_colIndex[]={0,0,1,2};
	int B_nonZeroCount=4;
	int MAX;
	if(A_nonZeroCount>B_nonZeroCount)MAX=A_nonZeroCount;
	else MAX=B_nonZeroCount;
	float C_values[MAX];
	int C_rowIndex[MAX];
	int C_colIndex[MAX];
	int C_nonZeroCount=0;
	
	clock_t start=clock();
	sparse_matmul_coo(A_values,A_rowIndex,A_colIndex,A_nonZeroCount,
                      B_values,B_rowIndex,B_colIndex,B_nonZeroCount,
					  C_values,C_rowIndex,C_colIndex,C_nonZeroCount);
					   
	clock_t end=clock();
	std::cout<<"基础的稀疏矩阵乘法时间："<< double(end-start)/CLOCKS_PER_SEC<<"秒"<<std::endl;
}