1384.cpp

哈尔滨工业大学ACM 竞赛网上在线试题集锦的源代码

/*  This Code is Submitted by wywcgs for Problem 1384 on 2005-03-12 at 12:36:59 */ 
#include <stdio.h>

int main()
{
    long N, limit;
    int a[11], length, i, flag;
    
    while(scanf("%ld", &N) == 1){
        if(N < 10){
            printf("%ld\n", N);
        }else if(N < 19){
            N = (N - 9) * 11;
            printf("%ld\n", N);
        }else if(N == 1999999999){
            printf("1000000000000000001\n");
        }else if(N == 2000000000){
            printf("1000000001000000001\n");
        }else{
            limit = 0;
            flag = 0;
            while(N > limit*2){
                limit = limit * 10 + 9;
            }
            limit /= 10;
            N -= limit * 2;
            if(N > (limit+1)*9){
                N -= (limit + 1) * 9;
                flag = 1;
            }
            N += limit;
            for(length = 0; N > 0; N /= 10, length++){
                a[length] = N % 10;
            }
            for(i = 0; i < length; i++){
                printf("%d", a[length-1-i]);
            }
            if(flag == 1){
                printf("%d", a[0]);
            }
            for(i = 1; i < length; i++){
                printf("%d", a[i]);
            }
            printf("\n");
        }
    }

    return 0;
}