学习来源1：日撸 Java 三百行（31-40天，图）
学习来源2：日撸 Java 三百行（41-50天，查找与排序）
输入：输入整型二维数组tempMatrix3构造网
输出：输出关键路径构造过程
优化目标：无
public boolean[] criticalPath() {
int tempValue;
int[] tempInDegrees = new int[numNodes];
for (int i = 0; i < numNodes; i++) {
for (int j = 0; j < numNodes; j++) {
if (weightMatrix.getValue(i, j) != -1) {
tempInDegrees[j]++;
} // Of if
} // Of for j
} // Of for i
System.out.println("In-degree of nodes: " + Arrays.toString(tempInDegrees));
int[] tempEarliestTimeArray = new int[numNodes];
for (int i = 0; i < numNodes; i++) {
if (tempInDegrees[i] > 0) {
continue;
} // Of if
System.out.println("Removing " + i);
for (int j = 0; j < numNodes; j++) {
if (weightMatrix.getValue(i, j) != -1) {
tempValue = tempEarliestTimeArray[i] + weightMatrix.getValue(i, j);
if (tempEarliestTimeArray[j] < tempValue) {
tempEarliestTimeArray[j] = tempValue;
} // Of if
tempInDegrees[j]--;
} // Of if
} // Of for j
} // Of for i
System.out.println("Earlest start time: " + Arrays.toString(tempEarliestTimeArray));
int[] tempOutDegrees = new int[numNodes];
for (int i = 0; i < numNodes; i++) {
for (int j = 0; j < numNodes; j++) {
if (weightMatrix.getValue(i, j) != -1) {
tempOutDegrees[i]++;
} // Of if
} // Of for j
} // Of for i
System.out.println("Out-degree of nodes: " + Arrays.toString(tempOutDegrees));
int[] tempLatestTimeArray = new int[numNodes];
for (int i = 0; i < numNodes; i++) {
tempLatestTimeArray[i] = tempEarliestTimeArray[numNodes - 1];
} // Of for i
for (int i = numNodes - 1; i >= 0; i--) {
if (tempOutDegrees[i] > 0) {
continue;
} // Of if
System.out.println("Removing " + i);
for (int j = 0; j < numNodes; j++) {
if (weightMatrix.getValue(j, i) != -1) {
tempValue = tempLatestTimeArray[i] - weightMatrix.getValue(j, i);
if (tempLatestTimeArray[j] > tempValue) {
tempLatestTimeArray[j] = tempValue;
} // Of if
tempOutDegrees[j]--;
System.out.println("The out-degree of " + j + " decreases by 1.");
} // Of if
} // Of for j
} // Of for i
System.out.println("Latest start time: " + Arrays.toString(tempLatestTimeArray));
boolean[] resultCriticalArray = new boolean[numNodes];
for (int i = 0; i < numNodes; i++) {
if (tempEarliestTimeArray[i] == tempLatestTimeArray[i]) {
resultCriticalArray[i] = true;
} // Of if
} // Of for i
System.out.println("Critical array: " + Arrays.toString(resultCriticalArray));
System.out.print("Critical nodes: ");
for (int i = 0; i < numNodes; i++) {
if (resultCriticalArray[i]) {
System.out.print(" " + i);
} // Of if
} // Of for i
System.out.println();
return resultCriticalArray;
}// Of criticalPath
public static void main(String args[]) {
Net tempNet0 = new Net(3);
System.out.println(tempNet0);
int[][] tempMatrix1 = { { 0, 9, 3, 6 }, { 5, 0, 2, 4 }, { 3, 2, 0, 1 }, { 2, 8, 7, 0 } };
Net tempNet1 = new Net(tempMatrix1);
System.out.println(tempNet1);
tempNet1.dijkstra(1);
int[][] tempMatrix2 = { { 0, 7, MAX_DISTANCE, 5, MAX_DISTANCE }, { 7, 0, 8, 9, 7 },
{ MAX_DISTANCE, 8, 0, MAX_DISTANCE, 5 }, { 5, 9, MAX_DISTANCE, 0, 15, },
{ MAX_DISTANCE, 7, 5, 15, 0 } };
Net tempNet2 = new Net(tempMatrix2);
tempNet2.prim();
int[][] tempMatrix3 = { { -1, 3, 2, -1, -1, -1 }, { -1, -1, -1, 2, 3, -1 },
{ -1, -1, -1, 4, -1, 3 }, { -1, -1, -1, -1, -1, 2 }, { -1, -1, -1, -1, -1, 1 },
{ -1, -1, -1, -1, -1, -1 } };
Net tempNet3 = new Net(tempMatrix3);
System.out.println("-------critical path");
tempNet3.criticalPath();
}// Of main
运行截图：
顺序查找使用岗哨可以节约一半的时间。 为此，第 0 个位置不可以放有意义的数据，即有效数据只有 length - 1 个。
顺序查找时间复杂度为 O(n)；折半查找时间复杂度为O(logn)。
输入：输入整型数组tempSortedKeys和字符数组tempContents构造数据数组tempDataArray
输出：通过顺序查找与折半查找输出指定key的元素中的内容content
优化目标：无
package my_java;
public class DataArray {
class DataNode {
int key;
String content;
DataNode(int paraKey, String paraContent) {
key = paraKey;
content = paraContent;
}// Of the second constructor
public String toString() {
return "(" + key + ", " + content + ") ";
}// Of toString
}// Of class DataNode
DataNode[] data;
int length;
public DataArray(int[] paraKeyArray, String[] paraContentArray) {
length = paraKeyArray.length;
data = new DataNode[length];
for (int i = 0; i < length; i++) {
data[i] = new DataNode(paraKeyArray[i], paraContentArray[i]);
} // Of for i
}// Of the first constructor
public String toString() {
String resultString = "I am a data array with " + length + " items.rn";
for (int i = 0; i < length; i++) {
resultString += data[i] + " ";
} // Of for i
return resultString;
}// Of toString
public String sequentialSearch(int paraKey) {
data[0].key = paraKey;
int i;
for (i = length - 1; data[i].key != paraKey; i--) {
;
}//Of for i
return data[i].content;
}// Of sequentialSearch
public static void sequentialSearchTest() {
int[] tempUnsortedKeys = { -1, 5, 3, 6, 10, 7, 1, 9 };
String[] tempContents = { "null", "if", "then", "else", "switch", "case", "for", "while" };
DataArray tempDataArray = new DataArray(tempUnsortedKeys, tempContents);
System.out.println(tempDataArray);
System.out.println("Search result of 10 is: " + tempDataArray.sequentialSearch(10));
System.out.println("Search result of 5 is: " + tempDataArray.sequentialSearch(5));
System.out.println("Search result of 4 is: " + tempDataArray.sequentialSearch(4));
}// Of sequentialSearchTest
public String binarySearch(int paraKey) {
int tempLeft = 0;
int tempRight = length - 1;
int tempMiddle = (tempLeft + tempRight) / 2;
while (tempLeft <= tempRight) {
tempMiddle = (tempLeft + tempRight) / 2;
if (data[tempMiddle].key == paraKey) {
return data[tempMiddle].content;
} else if (data[tempMiddle].key <= paraKey) {
tempLeft = tempMiddle + 1;
} else {
tempRight = tempMiddle - 1;
}
} // Of while
// Not found.
return "null";
}// Of binarySearch
public static void binarySearchTest() {
int[] tempSortedKeys = { 1, 3, 5, 6, 7, 9, 10 };
String[] tempContents = { "if", "then", "else", "switch", "case", "for", "while" };
DataArray tempDataArray = new DataArray(tempSortedKeys, tempContents);
System.out.println(tempDataArray);
System.out.println("Search result of 10 is: " + tempDataArray.binarySearch(10));
System.out.println("Search result of 5 is: " + tempDataArray.binarySearch(5));
System.out.println("Search result of 4 is: " + tempDataArray.binarySearch(4));
}// Of binarySearchTest
public static void main(String args[]) {
System.out.println("rn-------sequentialSearchTest-------");
sequentialSearchTest();
System.out.println("rn-------binarySearchTest-------");
binarySearchTest();
}// Of main
}// Of class DataArray
运行截图：
