用Swift3实现从中心开始，逆时针打印 n*n 矩阵

来源：互联网发布：单反照片导入mac 编辑：程序博客网时间：2024/06/05 17:32

从中心开始，逆时针打印 n*n 矩阵例如：[  0,  1,  2,  3][  4,  5,  6,  7][  8,  9, 10, 11][ 12, 13, 14, 15]输出：6,5,9,10,11,7,3,2,1,0,4,8,12,13,14,15func  printNN( n:Int){        var row = 0 ;    var col = 0;    if(n%2==0){//偶数行时        row = n/2;        col = row + 1;    }else{//奇数行时        row = (n+1)/2        col = row    }        var k = n - col //与外围相差多少个数字    var  s = "";//最终的字符串    if(k<0){ // n = re1 时        print("0")        return    }    while(k > -1){        for d in 0..<4{            switch(d){            case 0 ://向上                //                int i = row-1                let m = row - 2 ;                                if m >= 0 && m > k - 1  {                    var j = k                    if j < 0 {                        j = 0 ;                    }                    for i in (j ... m).reversed(){                        if(s == ""){                            s =  rowCol(row: i,col: col-1,n: n)                        }else{                            s =   s + "," + rowCol(row: i,col: col-1,n: n)                        }                    }                    row = k + 1  ;                    col  = col - 1 ;                    print(s + "===\(d)"  )                }                                break;                            case 1 ://向左                let m = col-1                if m >= 0 && m > k - 1 {                                        if n % 2 == 1 && m <= k {                        break                    }                    for i in (k ... m).reversed(){                        if(s == ""){                            s =  rowCol(row: row-1,col: i,n: n)                        }else{                            s =   s + "," + rowCol(row: row-1,col: i,n: n)                        }                    }                    row = row + 1 ;                    col  = k + 1 ;                    print(s + "===\(d)"  )                }                                break;                                            case 2 ://向下                let m = row - 1                let j = n-k                if m < j - 1 && m>=0{                    for i in m ..< j {                        if(s == ""){                            s =  rowCol(row: i,col: col-1,n: n)                        }else{                            s =   s + "," + rowCol(row: i,col: col-1,n: n)                        }                    }                    row = n - k ;                    col = col + 1 ;                    print(s + "===\(d)"  )                }                                break;            case 3 ://向右//                int i =                 let m = col - 1                var j = n - k                if k > 0 {                    j = j + 1                }                if m <= j - 1 && m >= 0 {                    for i in m ..< j {                        if(s == ""){                            s =  rowCol(row: row-1,col: i,n: n)                        }else{                            s =   s + "," + rowCol(row: row-1,col: i,n: n)                        }                    }//                    row = row - 1 ;                    col  = n - k + 1 ;                    print(s + "===\(d)"  )                }                                break;                       default:                break;                                            }        }        k -= 1;    }    print(s)}func  rowCol(row:Int  , col:Int,n:Int )->String{    return  String(row * n + col)}printNN(n: 6)
0 0