1 /* 2     水题：判断前后的差值是否为1，b[i]记录差值，若没有找到，则是第一个出错 3 */ 4 #include 
     
       5 #include 
      
        6 #include 
       
         7 #include 
        
          8 #include 
         
           9 #include 
          
           10 using namespace std;11 12 const int MAXN = 1e5 + 10;13 const int INF = 0x3f3f3f3f;14 int a[MAXN];15 int b[MAXN];16 17 int main(void) //HDOJ 4727 The Number Off of FFF18 {19 //freopen ("L.in", "r", stdin);20 21 int t, cas = 0;22 int n;23 scanf ("%d", &t);24 while (t--)25 {26 scanf ("%d", &n);27 28 a[0] = b[0] = 0;29 for (int i=1; i<=n; ++i)30 {31 scanf ("%d", &a[i]);32 b[i] = a[i] - a[i-1];33 }34 35 int ans = -1;36 for (int i=2; i<=n; ++i)37 {38 if (b[i] != 1)39 {40 ans = i; break;41 }42 }43 if (ans == -1) ans = 1;44 45 printf ("Case #%d: %d\n", ++cas, ans);46 }47 48 return 0;49 }50 51 /*52 Case #1: 353 Case #2: 354 */