modify code

src/class21/Code01_MinPathSum.java

@@ -28,22 +28,20 @@ public class Code01_MinPathSum {
 		if (m == null || m.length == 0 || m[0] == null || m[0].length == 0) {
 			return 0;
 		}
-		int more = Math.max(m.length, m[0].length); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ϴ<EFBFBD><CFB4><EFBFBD>Ǹ<EFBFBD>Ϊmore
-		int less = Math.min(m.length, m[0].length); // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>С<EFBFBD><D0A1><EFBFBD>Ǹ<EFBFBD>Ϊless
-		boolean rowmore = more == m.length; // <20><><EFBFBD><EFBFBD><EFBFBD>Dz<EFBFBD><C7B2>Ǵ<EFBFBD><C7B4>ڵ<EFBFBD><DAB5><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>
-		int[] arr = new int[less]; // <20><><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ij<EFBFBD><C4B3>Ƚ<EFBFBD>Ϊ<EFBFBD><CEAA><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>е<EFBFBD><D0B5><EFBFBD>Сֵ
-		arr[0] = m[0][0];
-		for (int i = 1; i < less; i++) {
-			arr[i] = arr[i - 1] + (rowmore ? m[0][i] : m[i][0]);
+		int row = m.length;
+		int col = m[0].length;
+		int[] dp = new int[col];
+		dp[0] = m[0][0];
+		for (int j = 1; j < col; j++) {
+			dp[j] = dp[j - 1] + m[0][j];
 		}
-		for (int i = 1; i < more; i++) {
-			arr[0] = arr[0] + (rowmore ? m[i][0] : m[0][i]);
-			for (int j = 1; j < less; j++) {
-				arr[j] = Math.min(arr[j - 1], arr[j])
-						+ (rowmore ? m[i][j] : m[j][i]);
+		for (int i = 1; i < row; i++) {
+			dp[0] += m[i][0];
+			for (int j = 1; j < col; j++) {
+				dp[j] = Math.min(dp[j - 1], dp[j]) + m[i][j];
 			}
 		}
-		return arr[less - 1];
+		return dp[col - 1];
 	}
 
 	// for test
@@ -54,7 +52,7 @@ public class Code01_MinPathSum {
 		int[][] result = new int[rowSize][colSize];
 		for (int i = 0; i != result.length; i++) {
 			for (int j = 0; j != result[0].length; j++) {
-				result[i][j] = (int) (Math.random() * 10);
+				result[i][j] = (int) (Math.random() * 100);
 			}
 		}
 		return result;
@@ -71,10 +69,9 @@ public class Code01_MinPathSum {
 	}
 
 	public static void main(String[] args) {
-		// int[][] m = generateRandomMatrix(3, 4);
-		int[][] m = { { 1, 3, 5, 9 }, { 8, 1, 3, 4 }, { 5, 0, 6, 1 },
-				{ 8, 8, 4, 0 } };
-		printMatrix(m);
+		int rowSize = 10;
+		int colSize = 10;
+		int[][] m = generateRandomMatrix(rowSize, colSize);
 		System.out.println(minPathSum1(m));
 		System.out.println(minPathSum2(m));
 

src/class21/Code02_CoinsWayEveryPaperDifferent.java

@@ -6,11 +6,12 @@ public class Code02_CoinsWayEveryPaperDifferent {
 		return process(arr, 0, aim);
 	}
 
+	// arr[index....] 组成正好rest这么多的钱，有几种方法
 	public static int process(int[] arr, int index, int rest) {
 		if (rest < 0) {
 			return 0;
 		}
-		if (index == arr.length) {
+		if (index == arr.length) { // 没钱了！
 			return rest == 0 ? 1 : 0;
 		} else {
 			return process(arr, index + 1, rest) + process(arr, index + 1, rest - arr[index]);

src/class21/Code03_CoinsWayNoLimit.java

@@ -9,8 +9,9 @@ public class Code03_CoinsWayNoLimit {
 		return process(arr, 0, aim);
 	}
 
+	// arr[index....] 所有的面值，每一个面值都可以任意选择张数，组成正好rest这么多钱，方法数多少？
 	public static int process(int[] arr, int index, int rest) {
-		if (index == arr.length) {
+		if (index == arr.length) { // 没钱了
 			return rest == 0 ? 1 : 0;
 		}
 		int ways = 0;

src/class21/Code04_CoinsWaySameValueSamePapper.java

@@ -43,6 +43,8 @@ public class Code04_CoinsWaySameValueSamePapper {
 		return process(info.coins, info.zhangs, 0, aim);
 	}
 
+	// coins 面值数组，正数且去重
+	// zhangs 每种面值对应的张数
 	public static int process(int[] coins, int[] zhangs, int index, int rest) {
 		if (index == coins.length) {
 			return rest == 0 ? 1 : 0;

src/class21/Code05_BobDie.java

@@ -1,18 +1,21 @@
-package class22;
+package class21;
 
-public class Code01_BobDie {
+public class Code05_BobDie {
 
 	public static double livePosibility1(int row, int col, int k, int N, int M) {
 		return (double) process(row, col, k, N, M) / Math.pow(4, k);
 	}
 
+	// 目前在row，col位置，还有rest步要走，走完了如果还在棋盘中就获得1个生存点，返回总的生存点数
 	public static long process(int row, int col, int rest, int N, int M) {
 		if (row < 0 || row == N || col < 0 || col == M) {
 			return 0;
 		}
+		// 还在棋盘中！
 		if (rest == 0) {
 			return 1;
 		}
+		// 还在棋盘中！还有步数要走
 		long up = process(row - 1, col, rest - 1, N, M);
 		long down = process(row + 1, col, rest - 1, N, M);
 		long left = process(row, col - 1, rest - 1, N, M);

src/class22/Code01_KillMonster.java

@@ -1,6 +1,6 @@
 package class22;
 
-public class Code02_KillMonster {
+public class Code01_KillMonster {
 
 	public static double right1(int N, int M, int K) {
 		if (N < 1 || M < 1 || K < 1) {

src/class22/Code02_MinCoinsNoLimit.java

@@ -1,6 +1,6 @@
 package class22;
 
-public class Code03_MinCoinsNoLimit {
+public class Code02_MinCoinsNoLimit {
 
 	public static int minCoins(int[] arr, int aim) {
 		return process(arr, 0, aim);

src/class22/Code03_SplitSumClosed.java

@@ -1,8 +1,8 @@
-package class23;
+package class22;
 
 import java.util.TreeSet;
 
-public class Code01_SplitSumClosed {
+public class Code03_SplitSumClosed {
 
 	public static int right(int[] arr) {
 		if (arr == null || arr.length < 2) {

src/class22/Code04_SplitSumClosedSizeHalf.java

@@ -1,8 +1,8 @@
-package class23;
+package class22;
 
 import java.util.TreeSet;
 
-public class Code02_SplitSumClosedSizeHalf {
+public class Code04_SplitSumClosedSizeHalf {
 
 	public static int right(int[] arr) {
 		if (arr == null || arr.length < 2) {

src/class23/Code01_NQueens.java

@@ -1,6 +1,6 @@
 package class23;
 
-public class Code03_NQueens {
+public class Code01_NQueens {
 
 	public static int num1(int n) {
 		if (n < 1) {

src/class23/Code02_MinCoinsOnePaper.java

@@ -1,10 +1,10 @@
-package class22;
+package class23;
 
 import java.util.HashMap;
 import java.util.Map.Entry;
 import java.util.LinkedList;
 
-public class Code04_MinCoinsOnePaper {
+public class Code02_MinCoinsOnePaper {
 
 	public static int minCoins(int[] arr, int aim) {
 		return process(arr, 0, aim);