/* --------------------------------------------------------------------------  * A Monte Carlo simulation of a stochastic activity network. * * Name              : San.java * Author            : Jeff Mallozzi, Kerry Connell, Larry Leemis,Matt Duggan * Translation by    : Richard Dutton * Language          : Java * Latest Revision   : 6-16-06 --------------------------------------------------------------------------- */import java.io.*;import java.text.*;import java.lang.Math;public class San{    static final int MAXEDGE = 50;    static final int MAXNODE = 50;    static final int MAXPATHS = 50;    static final long N = 10000;                 /* number of replications */    long   M[][];    long   Paths[][];    double UpperLimit[];    double p[];    long   paths;    long   nodes;    long   edges;    Rngs rngs;    public San(){	M = new long[MAXNODE][MAXEDGE];	Paths = new long[MAXPATHS][MAXNODE];	UpperLimit = new double[MAXEDGE];	p = new double[MAXEDGE];	rngs = new Rngs();    }    /* =========================== */    double uniform(double a, double b)          /* use a < b */    /* =========================== */    {	return (a + (b - a) * rngs.random());    }    /* ========================== */    void getActivityDurations()    /* ========================== */    {	int i;	for (i = 1; i <= edges; i++)	    p[i] = uniform(0.0, UpperLimit[i]);	return;    }    /* ================ */    void printPaths()    /* ================ */    {	int i;	int j;	System.out.println();	for (i = 1; i <= paths; i++) {	    System.out.print("Path " + i + ": ");	    j = 1;	    while(Paths[i][j] != 0) {		j++;	    }	    j--;	    while(j > 0) {		System.out.print("-" + Paths[i][j] + "-");		j--;	    }	    System.out.println();	}	return;    }    /* =============================== */    double timeToComplete(long node)    /* =============================== */    {	int   k;	long   l = 0;	double tmax   = 0.0;	double t  = 0.0;  	k = 1;	while (l < M[(int)node][0]) {	    if (M[(int)node][k] == -1) {		t = timeToComplete(M[0][k]) + p[k];		if (t >= tmax)		    tmax = t;		l++;	    }	    k++;	}	return(tmax);    }    /* ============================================= */    long getPaths(long node, long step, long path)    /* ============================================= */    {	int i = 1;	int j;	long found    = 0;	long numpaths = 0;	long total    = 0;  	while(found < M[(int)node][0]) {	    if(M[(int)node][i] == -1) {		numpaths = getPaths(M[0][i], step + 1, path + total);		for (j = 0; j < numpaths; j++) {		    Paths[(int)(path + j + total)][(int)step] = i;		}		total += numpaths;		found++;	    }	    i++;	}	if(total == 0) {	    Paths[(int)path][(int)step] = 0;	    total = 1;	}	return(total);    }    /* ============================================= */    void estimatePathProb()    /* ============================================= */    {	int i;	int j;	int k;	long   maxpath = -1;	long   PathProb[] = new long[MAXPATHS]; 	for(int c = 0; c<MAXPATHS; c++){	    PathProb[c] = 0;    	}	double pathtime           = 0.0;	double maxtime            = 0.0;  	for (i = 0; i < N; i++) {	    getActivityDurations();	    for (j = 1; j <= paths; j++) {		k = 1;		while(Paths[j][k] != 0) {		    pathtime += p[(int)Paths[j][k]];		    k++;		}		if(pathtime > maxtime) {		    maxtime = pathtime;		    maxpath = j;		}		pathtime = 0.0;	    }	    PathProb[(int)maxpath]++;    	    maxpath = 0;	    maxtime = 0.0;	}	DecimalFormat f2 = new DecimalFormat("0.000000");	System.out.print("\nCritical path probabilities:\n");	for (i = 1; i <= paths; i++)	    System.out.print(" -  " + i + "  - ");	System.out.println();	for (i = 1; i <= paths; i++)	    System.out.print(" " + f2.format((double) PathProb[i]/N));	System.out.println();	return;    }    /* =================== */    void defineNetwork()    /* =================== */    {	int j;	int k;	edges = 9;	nodes = 6;	for (j = 0; j <= nodes; j++) {	    for (k = 0; k <= edges; k++) {		M[j][k] = 0;	    }	}	M[1][1] = 1;	M[2][1] = -1;	M[1][2] = 1;	M[3][2] = -1;	M[1][3] = 1;	M[4][3] = -1;	M[2][4] = 1;	M[3][4] = -1;	M[2][5] = 1;	M[5][5] = -1;	M[3][6] = 1;	M[4][6] = -1;	M[3][7] = 1;	M[6][7] = -1;	M[4][8] = 1;	M[6][8] = -1;	M[5][9] = 1;	M[6][9] = -1;	for (j = 1; j <= nodes; j++) {	    for (k = 1; k <= edges; k++) {		if(M[j][k] == -1) {		    M[j][0]++;		}		else if(M[j][k] == 1) {		    M[0][k] = j;		}	    }	}	UpperLimit[1] = 3.0;	UpperLimit[2] = 6.0;	UpperLimit[3] = 13.0;	UpperLimit[4] = 9.0;	UpperLimit[5] = 3.0;	UpperLimit[6] = 9.0;	UpperLimit[7] = 7.0;	UpperLimit[8] = 6.0;	UpperLimit[9] = 3.0;	paths = getPaths(nodes, 1, 1);	System.out.print("Network read in:\n");	System.out.print(edges + " edges.\n");	System.out.print(nodes + " nodes.\n");	System.out.print(paths + " paths.\n");	return;    }    /* ============================ */    void estimateCompletionTime()    /* ============================ */    {	long   node;	long   i;	double time;	double sumtime = 0.0;  	node = nodes; 	for (i = 0; i < N; i++) {	    getActivityDurations();	    time = timeToComplete(node);	    sumtime += time; 	}	//printf("\nFor %ld replications,", N);	System.out.print("\nFor " + N + " replications,");	//printf("\nthe estimated average time to complete the network is:\n");	System.out.print("\nthe estimated average time to complete the network is:\n"); 	DecimalFormat f2 = new DecimalFormat("##########0.00000");	//printf("%11.5f\n", sumtime / (double) N);	System.out.println(f2.format(sumtime / (double) N));	return;    }      /* ============= */    public static void main(String args[])    /* ============= */    {	San san = new San();	san.run();    }    void run(){        defineNetwork();        printPaths();        rngs.putSeed(0);        estimateCompletionTime();        rngs.putSeed(0);        estimatePathProb();    }}