Sword refers to the offer series source-Rectangle Overlay

Topic 1390: Rectangular Coverage time limit: 1 seconds Memory limit: 32 Mega Special: No submission: 1409 resolution: 886 Title Description: We can use the small rectangle of 2*1 to cover the larger rectangle horizontally or vertically. What is the total number of ways to cover a large rectangle of 2*n with n 2*1 small rectangles without overlapping? Input: The input may contain multiple test samples, and for each test case, the input includes an integer n (1<=n<=70), where n is an even number. Output: For each test case, the output of the small rectangle with n 2*1 overlay a large rectangle of 2*n without overlapping, the total number of methods. Sample input: 4 Sample output: 5

#include <iostream> #include <stdio.h>using namespace std;//forwarding loop long  long f (int n) {    if (n==1) return 1;    if (n==2) return 2;    Long long sum=0;    Long Long preone=2;//n before a    long long pretwo=1;//n the first two for    (int i=3;i<=n;i++) {        sum = preone+pretwo;        Pretwo = PreOne;        PreOne = sum;    }    return sum;} int main () {    int n;    while (scanf ("%d", &n)!=eof) {        printf ("%ld\n", f (n));    }    return 0;}

Sword refers to the offer series source-Rectangle Overlay