Data commit

Task/24-game-Solve/C/24-game-solve.c

@@ -0,0 +1,83 @@
+#include <stdio.h>
+
+typedef struct {int val, op, left, right;} Node;
+
+Node nodes[10000];
+int iNodes;
+
+int b;
+float eval(Node x){
+    if (x.op != -1){
+        float l = eval(nodes[x.left]), r = eval(nodes[x.right]);
+        switch(x.op){
+            case 0: return l+r;
+            case 1: return l-r;
+            case 2: return r-l;
+            case 3: return l*r;
+            case 4: return r?l/r:(b=1,0);
+            case 5: return l?r/l:(b=1,0);
+        }
+    }
+    else return x.val*1.;
+}
+
+void show(Node x){
+    if (x.op != -1){
+        printf("(");
+        switch(x.op){
+            case 0: show(nodes[x.left]); printf(" + "); show(nodes[x.right]); break;
+            case 1: show(nodes[x.left]); printf(" - "); show(nodes[x.right]); break;
+            case 2: show(nodes[x.right]); printf(" - "); show(nodes[x.left]); break;
+            case 3: show(nodes[x.left]); printf(" * "); show(nodes[x.right]); break;
+            case 4: show(nodes[x.left]); printf(" / "); show(nodes[x.right]); break;
+            case 5: show(nodes[x.right]); printf(" / "); show(nodes[x.left]); break;
+        }
+        printf(")");
+    }
+    else printf("%d", x.val);
+}
+
+int float_fix(float x){ return x < 0.00001 && x > -0.00001; }
+
+void solutions(int a[], int n, float t, int s){
+    if (s == n){
+        b = 0;
+        float e = eval(nodes[0]);
+
+        if (!b && float_fix(e-t)){
+            show(nodes[0]);
+            printf("\n");
+        }
+    }
+    else{
+        nodes[iNodes++] = (typeof(Node)){a[s],-1,-1,-1};
+
+        for (int op = 0; op < 6; op++){
+            int k = iNodes-1;
+            for (int i = 0; i < k; i++){
+                nodes[iNodes++] = nodes[i];
+                nodes[i] = (typeof(Node)){-1,op,iNodes-1,iNodes-2};
+                solutions(a, n, t, s+1);
+                nodes[i] = nodes[--iNodes];
+            }
+        }
+
+        iNodes--;
+    }
+};
+
+int main(){
+    // define problem
+
+    int a[4] = {8, 3, 8, 3};
+    float t = 24;
+
+    // print all solutions
+
+    nodes[0] = (typeof(Node)){a[0],-1,-1,-1};
+    iNodes = 1;
+
+    solutions(a, sizeof(a)/sizeof(int), t, 1);
+
+    return 0;
+}