Created
December 23, 2015 13:53
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Using numbers 1, 3, 4, 6 and math operators +, -, *, / get the number 24
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public class MathPuzzle { | |
public static float getNumber(String eq) | |
{ | |
float[] stackArray = new float[100]; | |
int stackPointer = 0; | |
for (int i = 0; i < eq.length(); i++) { | |
char c = eq.charAt(i); | |
if ((c>='0') && (c<='9')) | |
{ | |
stackArray[stackPointer] = stackArray[stackPointer]*10+(c-'0'); | |
} | |
if (c=='+') | |
{ | |
stackPointer--; | |
stackArray[stackPointer] = stackArray[stackPointer] + stackArray[stackPointer+1]; | |
} | |
if (c=='-') | |
{ | |
stackPointer--; | |
stackArray[stackPointer] = stackArray[stackPointer] - stackArray[stackPointer+1]; | |
} | |
if (c=='*') | |
{ | |
stackPointer--; | |
stackArray[stackPointer] = stackArray[stackPointer] * stackArray[stackPointer+1]; | |
} | |
if (c=='/') | |
{ | |
stackPointer--; | |
stackArray[stackPointer] = stackArray[stackPointer] / stackArray[stackPointer+1]; | |
} | |
if (c==' ') | |
{ | |
stackPointer++; | |
stackArray[stackPointer] = 0; | |
} | |
} | |
return stackArray[0]; | |
} | |
/** | |
* @param args | |
*/ | |
public static void main(String[] args) { | |
System.out.println(getNumber("4 6/")); | |
String st1 = "1346"; | |
String dd = "+-*/"; | |
for (int l = 0; l < st1.length(); l++) | |
for (int m = 0; m < st1.length(); m++) | |
if (m!=l) | |
for (int n = 0; n < st1.length(); n++) | |
if ((n!=l) && (n!=m)) | |
for (int o = 0; o < st1.length(); o++) | |
if ((o!=l) && (o!=m) && (o!=n)) { | |
String sss = String.format("%c %c %c %c", st1.charAt(l), st1.charAt(m), st1.charAt(n), st1.charAt(o)); | |
for (int i = 0; i < dd.length(); i++) | |
for (int j = 0; j < dd.length(); j++) | |
for (int k = 0; k < dd.length(); k++) { | |
String eq = sss + dd.charAt(i) + dd.charAt(j) + dd.charAt(k); | |
float r = getNumber(eq); | |
if ((r>23.99) && (r<24.01)) | |
System.out.println(eq + " " + r); | |
} | |
} | |
} | |
} |
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Solution given in reverse Polish notation