36 lines
904 B
C++
36 lines
904 B
C++
#include <stdio.h>
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char str[102];
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int ok;
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int check(char ch){
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if(ch >= '0' && ch <= '9') return 1;
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if(ch == '.') return 2;
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return 0;
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}
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int main(){
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int dot, dignum, a, dotsum;
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while(gets(str)){
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dotsum = a = dot = dignum = 0;
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for(int i = 0; str[i]; ++i){
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ok = check(str[i]);
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if(!ok) break;
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if(ok == 1){
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dot = 0;
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++dignum;
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a = a * 10 + str[i] - '0';
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if(dignum > 3 || a > 255){
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ok = 0; break;
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}
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}else{
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dignum = a = 0;
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++dot; ++dotsum;
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if(dot > 1 || dotsum > 3){
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ok = 0; break;
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}
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}
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}
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if(dot || dotsum != 3) ok = 0;
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printf(ok ? "YES\n" : "NO\n");
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}
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return 0;
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}
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