diff --git a/QUSTOJ/1724.c b/QUSTOJ/1724.c
new file mode 100644
index 0000000..a0475bb
--- /dev/null
+++ b/QUSTOJ/1724.c
@@ -0,0 +1,34 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define DUR 0.001
+double func(double x)
+{
+    return (2*x*x*x)-(4*x*x)+3*x-6;
+}
+
+double dfs(double L, double Mid, double R)
+{
+    int t;
+    if(R-L < DUR) return R;
+
+    if(func(L)*func(Mid) <=0)
+    {
+        t= dfs(L,(L+Mid)/2,Mid);
+    }
+    else if(func(Mid)*func(R) <=0)
+    {
+        t= dfs(Mid,(Mid+R)/2,R);
+    }
+    return t;
+}
+
+int main()
+{
+    double a, b, c;
+    scanf("%lf,%lf",&a,&c);
+    b = (a+c)/2;
+    printf("x=%6.2f\n",dfs(a,b,c));
+    return 0;
+}