moved examples

1 files changed, 97 insertions, 0 deletions

diff --git a/examples/ex2.c b/examples/ex2.c
new file mode 100644
index 0000000..6368bee
--- /dev/null
+++ b/examples/ex2.c
@@ -0,0 +1,97 @@
+#include "tcclib.h"
+
+#define N 20
+
+int nb_num;
+int tab[N];
+int stack_ptr;
+int stack_op[N];
+int stack_res[60];
+int result;
+
+int find(int n, int i1, int a, int b, int op)
+{
+    int i, j;
+    int c;
+
+    if (stack_ptr >= 0) {
+        stack_res[3*stack_ptr] = a;
+        stack_op[stack_ptr] = op;
+        stack_res[3*stack_ptr+1] = b;
+        stack_res[3*stack_ptr+2] = n;
+        if (n == result)
+            return 1;
+        tab[i1] = n;
+    }
+    
+    for(i=0;i<nb_num;i++) {
+        for(j=i+1;j<nb_num;j++) {
+            a = tab[i];
+            b = tab[j];
+            if (a != 0 && b != 0) {
+
+                tab[j] = 0;
+                stack_ptr++;
+
+                if (find(a + b, i, a, b, '+'))
+                    return 1;
+                if (find(a - b, i, a, b, '-'))
+                    return 1;
+                if (find(b - a, i, b, a, '-'))
+                    return 1;
+                if (find(a * b, i, a, b, '*'))
+                    return 1;
+                if (b != 0) {
+                    c = a / b;
+                    if (find(c, i, a, b, '/'))
+                        return 1;
+                }
+
+                if (a != 0) {
+                    c = b / a;
+                    if (find(c, i, b, a, '/'))
+                        return 1;
+                }
+                
+                stack_ptr--;
+                tab[i] = a;
+                tab[j] = b;
+            }
+        }
+    }
+
+    return 0;
+}
+
+int main(int argc, char **argv)
+{
+    int i, res, p;
+    
+    if (argc < 3) {
+        printf("usage: %s: result numbers...\n"
+               "Try to find result from numbers with the 4 basic operations.\n", argv[0]);
+        exit(1);
+    }
+
+    p = 1;
+    result = atoi(argv[p]);
+    printf("result=%d\n", result);
+    nb_num = 0;
+    for(i=p+1;i<argc;i++) {
+        tab[nb_num++] = atoi(argv[i]);
+    }
+
+    stack_ptr = -1;
+    res = find(0, 0, 0, 0, ' ');
+    if (res) {
+        for(i=0;i<=stack_ptr;i++) {
+            printf("%d %c %d = %d\n", 
+                   stack_res[3*i], stack_op[i],
+                   stack_res[3*i+1], stack_res[3*i+2]);
+        }
+        return 0;
+    } else {
+        printf("Impossible\n");
+        return 1;
+    }
+}