二维矩阵螺旋遍历

//3.螺旋矩阵
//例如 n=4
//要求：打印出螺旋矩阵，求 i 行 j 列的数字，0<n<10000
//算法思想：只要找出每一层的第一个数即可，第一个数值为上一层的第一个数+4*n+4，循
//环时 n 每次减 2
//+--------------------------> X 轴
//| 1  2   3  4
// 12  13  14 5
//| 11 16 15  6
//| 10 9   8  7

#include <iostream>
using namespace std;
void input(int A[100][100],int n,int x,int y)
{
    int a = 0, b = 0, c = 0, d = 0;
    bool right = true, left = false, up = false, donw = false;
    for (int i = 0; i < n; i++) {
        scanf("%d", &A[a][b]);
        if (b == (y - 1) && right == true) {
            right = false;
            donw = true;
        } else if (a == (x - 1) && b == (y - 1) && donw == true) {
            left = true;
            donw = false;
        } else if (b == d && a == (x - 1) && left == true) {
            left = false;
            up = true;
            c++;
        } else if (c == a && b == d && up == true) {
            up = false;
            right = true;
            d++;
            x--;
            y--;
        }
        if (right == true)
            b++;
        else if (left == true)
            b--;
        else if (up == true)
            a--;
        else if (donw == true)
            a++;
    }
}//非递归调用螺旋输入

void print(int A[100][100],int n,int x,int y)
{
    int a = 0, b = 0, c = 0, d = 0;
    bool right = true, left = false, up = false, donw = false;
for (int i = 0; i < n; i++) {
    printf("%3d",A[a][b]);
if (b == (y - 1) && right == true) {
right = false;
donw = true;
} else if (a == (x - 1) && b == (y - 1) && donw == true) {
left = true;
donw = false;
} else if (b == d && a == (x - 1) && left == true) {
left = false;
up = true;
c++;
} else if (c == a && b == d && up == true) {
up = false;
right = true;
d++;
x--;
y--;
}
if (right == true)
b++;
else if (left == true)
b--;
else if (up == true)
a--;
else if (donw == true)
a++;
}
}//非递归调用螺旋打印

void Found(int A[100][100],int a,int b,int start,int x,int y) {
    if (x <= 0||y<=0)
        return;
    if (x*y == 1) {
        A[a][b] = start;
        return;
    }
    for (int i = b; i < b + y - 1; i++)//上部
        A[a][i] = start++;
    for (int j = a; j < a + x - 1; j++)//右边
        A[j][b + y - 1] = start++;
    for (int i = b + y - 1; i > b; i--)//底部
        A[a + x - 1][i] = start++;
    for (int j = a + x - 1; j > a; j--)//左边
        A[j][b] = start++;
    Found(A, a + 1, b + 1, start, x - 2,y-2);
}//递归调用螺旋输入

void Print(int A[100][100],int a,int b,int start,int x,int y) {
    if (x*y <= 0)
        return;
    if (x*y == 1) {
        printf("%3d",A[a][b]);
        return;
    }
    for (int i = b; i < b + y - 1; i++)//上部
        printf("%3d",A[a][i]);
    for (int j = a; j < x + a - 1; j++)//右边
         printf("%3d",A[j][y + b - 1]);
    for (int i = y + b - 1; i > b; i--)//底部
         printf("%3d",A[x + a - 1][i]);
    for (int j = x + a - 1; j > a; j--)//左边
         printf("%3d",A[j][b] );
    Print(A, a + 1, b + 1, start, x - 2,y-2);
}//递归调用螺旋打印

int main() {
    int A[100][100] = {0};
    int x, y, n;
    scanf("%d%d", &x,&y);
    n = x * y;
    input(A,n,x,y);//非递归螺旋矩阵输入
    print(A,n,x,y);//非递归螺旋矩阵螺旋打印

//    Found(A,0,0,1,x,y);//递归螺旋矩阵输入
//    Print(A,0,0,1,x,y);//递归螺旋矩阵打印
    printf("\n\n");
    for (int i = 0; i < x; i++) {
        for (int j = 0; j < y; j++)
            printf("%5d",A[i][j]);//按行和列正常打印
        cout << endl;
    }
}