螺旋矩阵定义:螺旋矩阵是指一个呈螺旋状的矩阵,它的数字由第一行开始到右边不断变大,向下变大,向左变大,向上变大,如此循环。
座标(4,3)对应的数字为34。
请定义一个函数,输入n,x,y(n为螺旋矩阵的阶数,x,y分别x轴、y轴座标),返回n阶螺旋矩阵座标(x,y)对应的数字。
#include<stdio.h> #include<assert.h> #define MIN(x, y) ({ \ typeof(x) _min1 = (x); \ typeof(y) _min2 = (y); \ (void) (&_min1 == &_min2); \ _min1 < _min2 ? _min1 : _min2; }) int getPointValue(int n, int _x, int _y); int main(){ int size = 0, x = 0, y = 0; printf("Please input 3 integers as the size, x and y of a 2-dimension matrix.\n"); scanf(" %u %u %u", &size, &x, &y); int result = getPointValue(size, x, y); return 0; } int getPointValue(int n, int _x, int _y){ assert(_x >= 1 && _x <= n); assert(_y >= 1 && _y <= n); const int ulimit = n - 1, x = _x - 1, y = _y - 1; int i, minIdx = -1, maxIdx = -1; int sval = 0, result = 0; minIdx = MIN( MIN(x, ulimit - x), MIN(y, ulimit - y) ); sval = 1; for(i=0; i<minIdx; ++i){ sval += (ulimit - i * 2) * 4; } maxIdx = ulimit - minIdx; if(y == minIdx){ result = sval + x - minIdx; } else if(x == maxIdx){ result = sval + (maxIdx - minIdx) + ( y - minIdx); } else if(y == maxIdx){ result = sval + (maxIdx - minIdx) * 2 + maxIdx - x; } else if (x == minIdx){ result = sval + (maxIdx - minIdx) * 3 + maxIdx - y; } else assert(0); printf("f(%u,%u,%u)=%u\n", n, _x, _y, result); return result; }