76 lines
1.7 KiB
Java
76 lines
1.7 KiB
Java
package DynamicProgramming;
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/*
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* this is an important Algo in which
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* we have starting and ending of board and we have to reach
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* we have to count no. of ways
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* that help to reach end point i.e number by rolling dice
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* which have 1 to 6 digits
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Test Case:
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here target is 10
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int n=10;
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startAlgo();
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System.out.println(bpR(0,n));
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System.out.println(endAlgo()+"ms");
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int[] strg=new int [n+1];
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startAlgo();
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System.out.println(bpRS(0,n,strg));
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System.out.println(endAlgo()+"ms");
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startAlgo();
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System.out.println(bpIS(0,n,strg));
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System.out.println(endAlgo()+"ms");
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*/
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public class BoardPath {
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public static long startTime;
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public static long endTime;
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public static void startAlgo() {
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startTime = System.currentTimeMillis();
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}
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public static long endAlgo() {
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endTime = System.currentTimeMillis();
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return endTime - startTime;
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}
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public static int bpR(int start, int end) {
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if (start == end) {
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return 1;
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} else if (start > end) return 0;
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int count = 0;
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for (int dice = 1; dice <= 6; dice++) {
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count += bpR(start + dice, end);
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}
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return count;
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}
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public static int bpRS(int curr, int end, int strg[]) {
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if (curr == end) {
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return 1;
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} else if (curr > end) return 0;
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if (strg[curr] != 0) return strg[curr];
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int count = 0;
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for (int dice = 1; dice <= 6; dice++) {
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count += bpRS(curr + dice, end, strg);
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}
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strg[curr] = count;
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return count;
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}
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public static int bpIS(int curr, int end, int[] strg) {
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strg[end] = 1;
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for (int i = end - 1; i >= 0; i--) {
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int count = 0;
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for (int dice = 1; dice <= 6 && dice + i < strg.length; dice++) {
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count += strg[i + dice];
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}
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strg[i] = count;
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}
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return strg[0];
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}
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}
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