题解 | #走方格的方案数#

#import <Foundation/Foundation.h>

int main(int argc, char* argv[]) {
    NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init];

    int m, n;
    scanf("%d%d", &m, &n);
    printf("%d", count(m, n));

    [pool drain];
    return 0;
}

int count(int m, int n) {
    if (m == 0 && n == 0) {
        return 0;
    }
    else if (m == 0 || n == 0) {
        return 1;
    }
    else {
        return count(m - 1, n) + count(m, n - 1);
    }
}