程序代码：

#include "mex.h"

void mexFunction(int nlhs, mxArray *plhs[], int nrhs, const mxArray *prhs[])
{
    int *inData;
    int *outData;
    int number;
    int M,N;
    int i,j,k,l;
    int count = 0;
    
    if(nrhs!=1) 
    {
        mexErrMsgTxt("One inputs required./n"); 
    }
    if(!mxIsDouble(prhs[0])) 
    {
        mexErrMsgTxt("the Input Matrix must be double!/n"); 
    }
    
    inData = mxGetPr(prhs[0]);
    M = mxGetM(prhs[0]);
    N = mxGetN(prhs[0]);
    plhs[0] = mxCreateDoubleMatrix(9,4,mxREAL);
    plhs[1] = mxCreateDoubleMatrix(1,1,mxREAL);
    outData = mxGetPr(plhs[0]);
    number = mxGetScalar(plhs[1]);

    for (i = 0; i < M; ++i)    
    {
        for (j = i+1; j < M; ++j)    
        {
            if (inData[i*M+j])    
            {
                for (k = j + 1; k < M; ++k)    
                {
                    if (inData[i*M+k] && inData[j*M+k])        
                    {
                        for (l = j+1; l < M; ++l)
                        {
                            if (!inData[k*M+l])                
                            {
                                if ((inData[i*M+l] && inData[j*M+l]) && (l>k))                      
                                {
                                    outData[count] = i+1;
                                    outData[9+count] = j+1;
                                    outData[18+count] = k+1;
                                    outData[27+count] = l+1;
                                    count += 1;
                                }
                            }            
                            else if (inData[k*M+l])
                            {
                                if ((inData[i*M+l] && !inData[j*M+l]) ||
                                (!inData[i*M+l] && inData[j*M+l]))                
                                {
                                    outData[count] = i+1;
                                    outData[9+count] = j+1;
                                    outData[18+count] = k+1;
                                    outData[27+count] = l+1;
                                    count += 1;
                                }
                            }                                            
                        }
                    }
                }
            }
        }
    }
    number = count;
}

程序代码：

% function [c4,n4] = findDTriangles( graph )
% c4: set of two triangles with two common nodes, k*4, each column is the nodes in two triangles
% n4: number of two triangles with two common nodes

graph = [ 0 1 1 1 1 0;
          1 0 1 1 1 0;
          1 1 0 0 1 0;
          1 1 0 0 1 1;
          1 1 1 1 0 1;
          0 0 0 1 1 0 ];
graph = sparse(graph);

[c4,n4] = GetDTriangles2(graph);