diff --git a/5.cpp b/5.cpp
new file mode 100644
index 0000000..2bf6855
--- /dev/null
+++ b/5.cpp
@@ -0,0 +1,66 @@
+#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;
+}
\ No newline at end of file