题解 | 交换到最大

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

static char res[2000000];
void ChangeID( char* a, char* b) {
    char temp = *a;
    *a = *b;
    *b = temp;
}
int ChangeMax( char* str ) {
    int iFlag = 1;
    int len = strlen(str);
    while ( iFlag ) {
        iFlag = 0;
        for ( int i = len - 1; i >= 1; i--) {
            if ( str[i] != '0' ) {
                if ( str[i] - '1' > str[i - 1] - '0') {
                    str[i]--;
                    ChangeID( &str[i - 1], &str[i]);
                    iFlag = 1;
                }
            }
        }
    }
    sprintf(res, "%s%s", res, str);
    return 0;
}

int main() {
    int n = 0;
    memset(res, 0x00,sizeof(res));
    scanf("%d", &n);

    char p[2000000];
    getchar();
    for ( int i = 0; i < n; i++) 
    {
        memset(p,0x00,sizeof(p));
        fgets( p, 2000000, stdin);
        ChangeMax(p);
    }

    printf("%s", res);
    return 0;
}