1 /** 2      * 找出未出现的最小正整数 3      * @param A 4      * @param n 5      * @date 2016-10-7 6      * @author shaobn 7      */ 8     public static int findArrayMex(int[] a,int n){ 9         int count = n;10         int temp = 0;11         int dir = 1;12         int num = 0;13         for(int i = 0;i<count-1;i++){14             if(a[i]>a[i+1]){15                 temp = a[i];16                 a[i]= a[i+1];17                 a[i+1] = temp;        18             }19             if(i==count-2){20                 count--;21                 i=-1;22             }23         }24         if(a[0]>1 || a[n-1]<1){25             return 1;26         }else {27             for(int i =0;i<n-1;i++){28                 if(a[i]>0){29                     num = i;30                     break;31                 }                32             }33             if(a[num]>1){34                 return 1;35             }else if(a[num]==1) {36                 for(int i =num+1;i<n-1;i++){37                     if(a[i]-a[num]>dir){38                         return a[num]+dir;39                     }else {40                         dir++;41                     }42                 }43             }44         }45         return a[num]+dir;46     }